draft-ietf-mmusic-sdp-atm-04.txt   draft-ietf-mmusic-sdp-atm-05.txt 
Internet Engineering Task Force Internet Engineering Task Force
Internet Draft Rajesh Kumar Internet Draft Rajesh Kumar
Document: draft-ietf-mmusic-sdp-atm-04.txt Mohamed Mostafa Document: draft-ietf-mmusic-sdp-atm-05.txt Mohamed Mostafa
January 9, 2001 Cisco Systems February 1, 2001 Cisco Systems
Expires: July 9, 2001 Expires: August 1, 2001
Conventions for the use of the Session Description Protocol (SDP) Conventions for the use of the Session Description Protocol (SDP)
for ATM Bearer Connections for ATM Bearer Connections
STATUS OF THIS DOCUMENT STATUS OF THIS DOCUMENT
This document is an Internet-Draft and is in full conformance with This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026. all provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
skipping to change at line 42 skipping to change at line 42
Abstract Abstract
This document describes conventions for using the Session Description This document describes conventions for using the Session Description
Protocol (SDP) described in RFC2327 [1] for controlling ATM Bearer Protocol (SDP) described in RFC2327 [1] for controlling ATM Bearer
Connections, and any associated ATM Adaptation Layer (AAL). The AALs Connections, and any associated ATM Adaptation Layer (AAL). The AALs
addressed are Type 1, Type 2 and Type 5. This list of conventions is addressed are Type 1, Type 2 and Type 5. This list of conventions is
meant to be exhaustive. Individual applications can use subsets of meant to be exhaustive. Individual applications can use subsets of
these conventions. Further, these conventions are meant to comply these conventions. Further, these conventions are meant to comply
strictly with the SDP syntax as defined in rfc2327. strictly with the SDP syntax as defined in rfc2327.
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1. Introduction...............................................................3 1. Introduction...............................................................3
2. Representation of Certain Fields within SDP description lines..............4 1.1 Key words to indicate Requirement Levels..................................4
2.1 Representation of Extension Attributes.................................4 2. Representation of Certain Fields within SDP description lines..............5
2.1 Representation of Extension Attributes.................................5
2.2 Representation of Parameter Values.....................................5 2.2 Representation of Parameter Values.....................................5
2.3 Directionality Convention..............................................5 2.3 Directionality Convention..............................................6
2.4 Case convention.........................................................7 2.4 Case convention.........................................................7
2.5 Use of special characters in SDP parameter values.......................7 2.5 Use of special characters in SDP parameter values.......................7
3. Capabilities Provided by SDP conventions..................................7 3. Capabilities Provided by SDP conventions..................................7
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4. Format of the ATM Session Description......................................9 4. Format of the ATM Session Description......................................9
5. Structure of the Session Description Lines...............................11 5. Structure of the Session Description Lines...............................11
5.1 The Origin Line........................................................11 5.1 The Origin Line........................................................11
5.2 The Session Name Line..................................................12 5.2 The Session Name Line..................................................12
5.3 The Connection Information Line........................................12 5.3 The Connection Information Line........................................12
5.4 The Timestamp Line.....................................................14 5.4 The Timestamp Line.....................................................14
5.5 Media Information Line for ATM connections.............................15 5.5 Media Information Line for ATM connections.............................15
5.5.1 The Virtual Connection ID.........................................15 5.5.1 The Virtual Connection ID.........................................15
5.5.2 The Transport Parameter...........................................17 5.5.2 The Transport Parameter...........................................18
5.5.3 The Format List for AAL1 and AAL5 applications....................19 5.5.3 The Format List for AAL1 and AAL5 applications....................19
5.5.4 The Format List for AAL2 applications.............................19 5.5.4 The Format List for AAL2 applications.............................19
5.5.5 Media information line construction...............................19 5.5.5 Media information line construction...............................20
5.6 The Media Attribute Lines..............................................24 5.6 The Media Attribute Lines..............................................24
5.6.1 ATM bearer connection attributes..................................25 5.6.1 ATM bearer connection attributes..................................25
5.6.1.1 The 'eecid' attribute...........................................27 5.6.1.1 The 'eecid' attribute...........................................27
5.6.1.2 The 'aalType' attribute.........................................28 5.6.1.2 The 'aalType' attribute.........................................28
5.6.1.3 The 'capability' attribute......................................29 5.6.1.3 The 'capability' attribute......................................29
5.6.1.4 The 'qosClass' attribute........................................30 5.6.1.4 The 'qosClass' attribute........................................30
5.6.1.5 The 'bcob' attribute............................................30 5.6.1.5 The 'bcob' attribute............................................30
5.6.1.6 The 'stc' attribute.............................................31 5.6.1.6 The 'stc' attribute.............................................31
5.6.1.7 The 'upcc' attribute............................................31 5.6.1.7 The 'upcc' attribute............................................32
5.6.1.8 The 'atmQOSfparms' and 'atmQOSbparms' attributes................32 5.6.1.8 The 'atmQOSparms' attribute.....................................32
5.6.1.9 The 'atmFtrfcDesc' and 'atmBtrfcDesc' attributes................33 5.6.1.9 The 'atmTrfcDesc' attribute....................................33
5.6.1.10 The 'abrFparms' and 'abrBparms' attributes......................35 5.6.1.10 The 'abrParms' attribute........................................36
5.6.1.11 The 'abrSetup' attribute........................................36 5.6.1.11 The 'abrSetup' attribute........................................37
5.6.1.12 The 'bearerType' attribute......................................37 5.6.1.12 The 'bearerType' attribute......................................38
5.6.1.13 The 'lij' attribute.............................................38 5.6.1.13 The 'lij' attribute.............................................39
5.6.1.14 The 'anycast' attribute.........................................38 5.6.1.14 The 'anycast' attribute.........................................39
5.6.1.15 The 'cache' attribute...........................................39 5.6.1.15 The 'cache' attribute...........................................40
5.6.1.16 The 'bearerSigIE' attribute.....................................39 5.6.1.16 The 'bearerSigIE' attribute.....................................41
5.6.2 ATM Adaptation Layer (AAL) attributes.............................40 5.6.2 ATM Adaptation Layer (AAL) attributes.............................41
5.6.2.1 The 'aalApp' attribute..........................................41 5.6.2.1 The 'aalApp' attribute..........................................42
5.6.2.2 The 'cbrRate' attribute.........................................43 5.6.2.2 The 'cbrRate' attribute.........................................44
5.6.2.3 The 'sbc' attribute.............................................44 5.6.2.3 The 'sbc' attribute.............................................45
5.6.2.4 The 'clkrec' attribute..........................................45 5.6.2.4 The 'clkrec' attribute..........................................47
5.6.2.5 The 'fec' attribute.............................................46 5.6.2.5 The 'fec' attribute.............................................47
5.6.2.6 The 'prtfl' attribute...........................................46 5.6.2.6 The 'prtfl' attribute...........................................47
5.6.2.7 The 'structure' attribute.......................................47 5.6.2.7 The 'structure' attribute.......................................48
5.6.2.8 The 'fcpsSDUsize' and 'bcpsSDUsize' attributes..................47 5.6.2.8 The 'cpsSDUsize' attribute......................................48
5.6.2.9 The 'aal2CPS' attribute.........................................48 5.6.2.9 The 'aal2CPS' attribute.........................................49
5.6.2.10 The 'aal2CPSSDUrate' attribute..................................48 5.6.2.10 The 'aal2CPSSDUrate' attribute..................................49
5.6.2.11 The 'aal2sscs3661unassured' attribute...........................48 5.6.2.11 The 'aal2sscs3661unassured' attribute...........................50
5.6.2.12 The 'aal2sscs3661assured' attribute.............................49 5.6.2.12 The 'aal2sscs3661assured' attribute.............................51
5.6.2.13 The 'aal2sscs3662' attribute....................................50
5.6.2.14 The 'aal5sscop' attribute.......................................52
5.6.3 Service attributes................................................52
5.6.3.1 The 'atmmap' attribute..........................................53
5.6.3.2 The 'silenceSupp' attribute.....................................58
5.6.3.3 The 'ecanf' and 'ecanb' attributes..............................59
5.6.3.4 The 'gcf' and 'gcb' attributes..................................60
5.6.3.5 The 'profileDesc' attribute.....................................60
5.6.3.6 The 'vsel' attribute............................................62
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5.6.3.7 The 'dsel' attribute............................................63 5.6.2.13 The 'aal2sscs3662' attribute....................................52
5.6.3.8 The 'fsel' attribute............................................64 5.6.2.14 The 'aal5sscop' attribute.......................................53
5.6.3.9 The 'codecconfig' attribute.....................................66 5.6.3 Service attributes................................................54
5.6.3.10 The 'isup_usi' attribute........................................66 5.6.3.1 The 'atmmap' attribute..........................................55
5.6.4 Miscellaneous media attributes...................................67 5.6.3.2 The 'silenceSupp' attribute.....................................59
5.6.4.1 The 'chain' attribute............................................67 5.6.3.3 The 'ecan' attribute............................................60
5.6.5 Use of the second media-level part in H.323 Annex C applications.68 5.6.3.4 The 'gc' attributes.............................................61
5.6.6 Use of the eecid media attribute in call establishment procedures 68 5.6.3.5 The 'profileDesc' attribute.....................................62
6.0 List of Parameters with Representations...............................73 5.6.3.6 The 'vsel' attribute............................................63
7.0 Examples of ATM session descriptions using SDP.........................82 5.6.3.7 The 'dsel' attribute............................................65
8.0 Security Considerations..................................................83 5.6.3.8 The 'fsel' attribute............................................66
8.1 Bearer Security.......................................................83 5.6.3.9 The 'onewaySel' attribute.......................................68
8.2 Security of the SDP description.......................................83 5.6.3.10 The 'codecconfig' attribute....................................69
9.0 ATM SDP Grammar.........................................................84 5.6.3.11 The 'isup_usi' attribute........................................70
5.6.3.12 The 'uiLayer1_Prot' attribute...................................70
5.6.4 Miscellaneous media attributes...................................71
5.6.4.1 The 'chain' attribute............................................71
5.6.5 Use of the second media-level part in H.323 Annex C applications.72
5.6.6 Use of the eecid media attribute in call establishment procedures 72
6.0 List of Parameters with Representations...............................77
7.0 Examples of ATM session descriptions using SDP.........................86
8.0 Security Considerations..................................................87
8.1 Bearer Security.......................................................87
8.2 Security of the SDP description.......................................88
9.0 ATM SDP Grammar.........................................................88
1. Introduction 1. Introduction
SDP will be used in conjunction with a connection handling /device SDP will be used in conjunction with a connection handling /device
control protocol such as Megaco (H.248) [26], SIP [18] or MGCP [25] to control protocol such as Megaco (H.248) [26], SIP [18] or MGCP [25] to
communicate the information needed to set up ATM and AAL2 bearer communicate the information needed to set up ATM and AAL2 bearer
connections. These connections include voice connections, voiceband data connections. These connections include voice connections, voiceband data
connections, clear channel circuit emulation connections, video connections connections, clear channel circuit emulation connections, video connections
and baseband data connections (such as fax relay, modem relay, SSCOP, and baseband data connections (such as fax relay, modem relay, SSCOP,
frame relay etc.). frame relay etc.).
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manner on receiving session descriptions based on the SDP conventions manner on receiving session descriptions based on the SDP conventions
in this document. This is done by extending the values of fields defined in in this document. This is done by extending the values of fields defined in
rfc2327 rather than by defining new fields. This is true for all SDP lines rfc2327 rather than by defining new fields. This is true for all SDP lines
except the of the media attribute lines, in which case new except the of the media attribute lines, in which case new
attributes are defined. The SDP protocol allows the definition attributes are defined. The SDP protocol allows the definition
of new attributes in the media attribute lines which are free-form. of new attributes in the media attribute lines which are free-form.
For the remaining lines, the fact that the <networkType> field in For the remaining lines, the fact that the <networkType> field in
an SDP descriptor is set to "ATM" should preclude the misinterpretation of an SDP descriptor is set to "ATM" should preclude the misinterpretation of
extended parameter values by rfc2327-compliant SDP parsers. extended parameter values by rfc2327-compliant SDP parsers.
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These conventions are meant to address the following ATM applications: These conventions are meant to address the following ATM applications:
1. Applications in which a new SVC is set-up for each service 1. Applications in which a new SVC is set-up for each service
connection. These SVCs could be AAL1 or AAL5 SVCs or connection. These SVCs could be AAL1 or AAL5 SVCs or
single-CID AAL2 SVCs. single-CID AAL2 SVCs.
2. Applications in which existing path resources are assigned 2. Applications in which existing path resources are assigned
to service connections. These resources could be: to service connections. These resources could be:
* AAL1/AAL5 PVCs, SPVCs or cached SVCs, * AAL1/AAL5 PVCs, SPVCs or cached SVCs,
* AAL2 single-CID PVCs, SPVCs or cached SVCs, * AAL2 single-CID PVCs, SPVCs or cached SVCs,
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* CIDs within AAL2 SVCs/PVCs/SPVCs that multiplex multiple * CIDs within AAL2 SVCs/PVCs/SPVCs that multiplex multiple
CIDs. CIDs.
Note that the difference between PVCs and SPVCs is in the way the bearer Note that the difference between PVCs and SPVCs is in the way the bearer
virtual circuit connection is set up. SPVCs are a class of PVCs that use virtual circuit connection is set up. SPVCs are a class of PVCs that use
bearer signaling, as opposed to node-by-node provisioning, for connection bearer signaling, as opposed to node-by-node provisioning, for connection
establishment. establishment.
This document is limited to the case when the network type is ATM. This document is limited to the case when the network type is ATM.
This includes raw RTP encapsulation [45] or voice sample encapsulation This includes raw RTP encapsulation [45] or voice sample encapsulation
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be coded. Although the descriptions shown here are encoded as text, be coded. Although the descriptions shown here are encoded as text,
alternate codings are possible: alternate codings are possible:
- Binary encoding such as ASN.1. This is an option (in addition to - Binary encoding such as ASN.1. This is an option (in addition to
text encoding) in the Megaco context. text encoding) in the Megaco context.
- Use of extended ISUP parameters [36] to encode the information in - Use of extended ISUP parameters [36] to encode the information in
SDP descriptors, with conversion to/from binary/text-based SDP SDP descriptors, with conversion to/from binary/text-based SDP
encoding when needed. encoding when needed.
1.1 Key words to indicate Requirement Levels
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The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD",
"SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to
be interpreted as described in rfc2119 [62].
2. Representation of Certain Fields within SDP description lines 2. Representation of Certain Fields within SDP description lines
This document conforms to the syntactic conventions of standard SDP as This document conforms to the syntactic conventions of standard SDP as
defined in RFC2327 [1]. defined in RFC2327 [1].
2.1 Representation of Extension Attributes 2.1 Representation of Extension Attributes
The SDP protocol [1] requires that non-standard attributes and codec The SDP protocol [1] requires that non-standard attributes and codec
names use an "X-" prefix. names use an "X-" prefix.
In this internet draft, the "X-" prefix is used consistently for In this internet draft, the "X-" prefix is used consistently for
codec names (Table 2) that have not been registered with the IANA. codec names (Table 2) that have not been registered with the IANA.
The IANA-registered codec names listed in [31] do not The IANA-registered codec names listed in [31] do not
use this prefix, regardless of whether they are statically or use this prefix, regardless of whether they are statically or
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dynamically assigned payload types. dynamically assigned payload types.
However, this prefix is not used for the extension SDP attributes However, this prefix is not used for the extension SDP attributes
defined in this document. This has been done to enhance legibility. defined in this document. This has been done to enhance legibility.
This document suggests that parsers be flexible in the use of the This document suggests that parsers be flexible in the use of the
"X-" prefix convention. They should accept codec names and attribute "X-" prefix convention. They should accept codec names and attribute
names with or without the "X-" prefix. names with or without the "X-" prefix.
2.2 Representation of Parameter Values 2.2 Representation of Parameter Values
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For both decimal and hex representations, if the underlying bit field For both decimal and hex representations, if the underlying bit field
is smaller or larger than the binary equivalent of the SDP representation, is smaller or larger than the binary equivalent of the SDP representation,
then leading 0 bits should be added or removed as needed. Thus, 3 and then leading 0 bits should be added or removed as needed. Thus, 3 and
0x3 translate into the following five-bit pattern: 0 0011. The SDP 0x3 translate into the following five-bit pattern: 0 0011. The SDP
representations 0x12 and 18 translate into the following five-bit representations 0x12 and 18 translate into the following five-bit
pattern: 1 0010. pattern: 1 0010.
Leading 0 digits shall not be used in decimal representations. Leading 0 digits shall not be used in decimal representations.
Generally, these are also not used in hexadecimal Generally, these are also not used in hexadecimal
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representations. Exceptions are when an exact number of hex digits representations. Exceptions are when an exact number of hex digits
is expected, as in the case of NSAP addresses. Parsers shall not is expected, as in the case of NSAP addresses. Parsers shall not
reject leading zeros in hex values. reject leading zeros in hex values.
Both single-character and multi-character string values are enclosed in Both single-character and multi-character string values are enclosed in
double quotes (i.e. "). By contrast, single quotes (i.e. ') are used for double quotes (i.e. "). By contrast, single quotes (i.e. ') are used for
emphasizing keywords rather than to refer to characters or strings. emphasizing keywords rather than to refer to characters or strings.
In the text representation of decimal and hex numbers, digits to the In the text representation of decimal and hex numbers, digits to the
left are more significant than digits to the right. left are more significant than digits to the right.
2.3 Directionality Convention 2.3 Directionality Convention
This section defined the meaning of the terms 'forward' and This section defined the meaning of the terms 'forward' and
'backward' as used in this document. This is specially applicable 'backward' as used in this document. This is specially applicable
to parameters that have a specific direction associated with them. to parameters that have a specific direction associated with them.
In this document, 'forward' refers to the direction away from the In this document, 'forward' refers to the direction away from the
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ATM node under consideration, while 'backward' refers to the direction ATM node under consideration, while 'backward' refers to the direction
towards the ATM node. This convention must be used in all SDP-based towards the ATM node. This convention must be used in all SDP-based
session descriptions regardless of whether underlying bearer is an SVC, a session descriptions regardless of whether underlying bearer is an SVC, a
dynamically allocated PVC/SPVC or a dynamically allocated CID. This dynamically allocated PVC/SPVC or a dynamically allocated CID. This
is regardless of which side originates the service connection. If ATM is regardless of which side originates the service connection. If ATM
SVC or AAL2 Q.2630.1 signaling is used, the directionality convention SVC or AAL2 Q.2630.1 signaling is used, the directionality convention
is independent of which side originates the SVC or AAL2 connection. is independent of which side originates the SVC or AAL2 connection.
This provides a simple way of identifying the direction in which a This provides a simple way of identifying the direction in which a
parameter is applicable, in a manner that is independent of the parameter is applicable, in a manner that is independent of the
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gateway originating a service-level call. In the backward SVC call set-up gateway originating a service-level call. In the backward SVC call set-up
model, this gateway terminates (rather than originates) an SVC call. The model, this gateway terminates (rather than originates) an SVC call. The
media gateway refers to the traffic descriptor (and hence the PCR) in the media gateway refers to the traffic descriptor (and hence the PCR) in the
direction away from this gateway as the forward traffic descriptor and direction away from this gateway as the forward traffic descriptor and
forward PCR. Clearly, this is at odds with ATM SVC signaling which refers forward PCR. Clearly, this is at odds with ATM SVC signaling which refers
to this very PCR as the backward PCR. The gateway needs to be able to to this very PCR as the backward PCR. The gateway needs to be able to
perform the required swap of directions. In this example, the media perform the required swap of directions. In this example, the media
gateway terminating the service level call (and hence originating the SVC gateway terminating the service level call (and hence originating the SVC
call) does not need to perform this swap. call) does not need to perform this swap.
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directions. Examples are the atmQOSfparms, atmFtrfcDesc, abrFparms and Certain parameters within attributes are defined exclusively
fcpsSDUsize for the forward direction, and atmQOSbparms, atmBtrfcDesc, for the forward or backward directions. Examples for the forward
abrBparms and bcpsSDUsize for the backward direction. Certain parameters direction are the <fsssar> subparameter within the
within attributes are defined exclusively for the forward or backward 'aal2sscs3661unassured' media attribute line,
directions. Examples for the forward direction are the <fsssar>
subparameter within the 'aal2sscs3661unassured' media attribute line,
the <fsssar>, <fsscopsdu> and <fsscopuu> subparameters within the the <fsssar>, <fsscopsdu> and <fsscopuu> subparameters within the
'aal2sscs3661assured' media attribute line, the <fsscopsdu> and 'aal2sscs3661assured' media attribute line, the <fsscopsdu> and
<fsscopuu> subparameters within the 'aal5sscop' media attribute line, <fsscopuu> subparameters within the 'aal5sscop' media attribute line,
and the <fmaxFrame> parameter within the 'aal2sscs3662' media attribute and the <fmaxFrame> parameter within the 'aal2sscs3662' media attribute
line. Examples for the backward direction are the <bsssar> line. Examples for the backward direction are the <bsssar>
subparameter within the 'aal2sscs3661unassured' media attribute line, subparameter within the 'aal2sscs3661unassured' media attribute line,
the <bsssar>, <bsscopsdu> and <bsscopuu> subparameters within the the <bsssar>, <bsscopsdu> and <bsscopuu> subparameters within the
'aal2sscs3661assured' media attribute line, the <bsscopsdu> and 'aal2sscs3661assured' media attribute line, the <bsscopsdu> and
<bsscopuu> subparameters within the 'aal5sscop' media attribute line, <bsscopuu> subparameters within the 'aal5sscop' media attribute line,
and the <bmaxFrame> parameter within the 'aal2sscs3662' media attribute and the <bmaxFrame> parameter within the 'aal2sscs3662' media attribute
line. line.
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For applications such as SIP, both the forward and backward attributes,
and the forward and backward subparameters within attributes can be
placed within the same SDP descriptor. In other applications
(such as Megaco-based applications), the appropriate place for the
forward attributes and subparameters within attributes is the remote
descriptor, while the appropriate place for the backward
attributes and subparameters within attributes is the local
descriptor.
2.4 Case convention 2.4 Case convention
As defined in RFC2327 [1], SDP syntax is case-sensitive. Since these ATM As defined in RFC2327 [1], SDP syntax is case-sensitive. Since these ATM
conventions conform strictly with SDP syntax, they are case-sensitive. SDP conventions conform strictly with SDP syntax, they are case-sensitive. SDP
line types (e.g. "c", "m", "o", "a") and fields in the SDP lines should be line types (e.g. "c", "m", "o", "a") and fields in the SDP lines should be
built according to the case conventions in [1] and in this document. It is built according to the case conventions in [1] and in this document. It is
suggested, but not required, that SDP parsers for ATM applications be case- suggested, but not required, that SDP parsers for ATM applications be case-
tolerant where ignoring case does not result in ambiguity. tolerant where ignoring case does not result in ambiguity.
2.5 Use of special characters in SDP parameter values 2.5 Use of special characters in SDP parameter values
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descriptor. If the use of these special characters is construed as a descriptor. If the use of these special characters is construed as a
violation of rfc2327 [1] syntax, then reserved string values can be used. violation of rfc2327 [1] syntax, then reserved string values can be used.
The string "CHOOSE" can be used in lieu of "$". The string "OMIT" can be The string "CHOOSE" can be used in lieu of "$". The string "OMIT" can be
used in lieu of "-" for an omitted parameter. A decision to use special used in lieu of "-" for an omitted parameter. A decision to use special
characters or reserved keywords will be made before this internet draft characters or reserved keywords will be made before this internet draft
is upgraded to an rfc. is upgraded to an rfc.
3. Capabilities Provided by SDP conventions 3. Capabilities Provided by SDP conventions
To support the applications listed in section 1, the SDP conventions in To support the applications listed in section 1, the SDP conventions in
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this document provide the following session control capabilities: this document provide the following session control capabilities:
* Identification of the underlying bearer network type as ATM. * Identification of the underlying bearer network type as ATM.
* Identification by an ATM network element of its own address, * Identification by an ATM network element of its own address,
in one of several possible formats. A connection peer can in one of several possible formats. A connection peer can
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initiate SVC set-up to this address. A call agent or connection initiate SVC set-up to this address. A call agent or connection
peer can select an pre-established bearer path to this address. peer can select an pre-established bearer path to this address.
* Identification of the ATM bearer connection that is to be * Identification of the ATM bearer connection that is to be
bound to the service-level connection. This is either bound to the service-level connection. This is either
a VCC in AAL1/AAL2/AAL5 applications or a channel (identified by a VCC in AAL1/AAL2/AAL5 applications or a channel (identified by
a CID) in AAL2 applications. a CID) in AAL2 applications.
* Identification of media type: audio, video, data. * Identification of media type: audio, video, data.
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capability/service category, broadband bearer class, traffic capability/service category, broadband bearer class, traffic
parameters, CPS parameters and SSCS parameters related the underlying parameters, CPS parameters and SSCS parameters related the underlying
bearer connection. bearer connection.
* Means for enabling or describing special functions such as leaf- * Means for enabling or describing special functions such as leaf-
initiated-join, anycast and SVC caching. initiated-join, anycast and SVC caching.
* For H.323 Annex C applications, a means of specifying the IP address * For H.323 Annex C applications, a means of specifying the IP address
and port number on which the node will receive RTCP messages. and port number on which the node will receive RTCP messages.
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* A means of chaining consecutive SDP descriptors so that they refer to * A means of chaining consecutive SDP descriptors so that they refer to
different layers of the same connection. different layers of the same connection.
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4. Format of the ATM Session Description 4. Format of the ATM Session Description
The sequence of lines in the session descriptions in this document The sequence of lines in the session descriptions in this document
conforms to rfc2327 [1]. In general, a session description consists of conforms to rfc2327 [1]. In general, a session description consists of
a session-level part followed by zero or more media-level parts. ATM a session-level part followed by zero or more media-level parts. ATM
session descriptions consist of a session-level part followed by one session descriptions consist of a session-level part followed by one
or two media-level parts. The only two media applicable are the ATM or two media-level parts. The only two media applicable are the ATM
bearer medium and RTCP control (where applicable). bearer medium and RTCP control (where applicable).
The session level part consists of the following lines: The session level part consists of the following lines:
skipping to change at line 472 skipping to change at line 465
In general, the 'v', 'o', 's', and 't' lines are mandatory. In general, the 'v', 'o', 's', and 't' lines are mandatory.
However, in the Megaco [26] context, these lines have been made optional. However, in the Megaco [26] context, these lines have been made optional.
The 'o', 's', and 't' lines are omitted in most MGCP [25] applications. The 'o', 's', and 't' lines are omitted in most MGCP [25] applications.
Note that SDP session descriptors for ATM can contain bandwidth (b=) and Note that SDP session descriptors for ATM can contain bandwidth (b=) and
encryption key (k=) lines. Like all other lines, these lines should encryption key (k=) lines. Like all other lines, these lines should
strictly conform to the SDP standard [1]. strictly conform to the SDP standard [1].
The bandwidth (b=) line is not necessarily redundant in the ATM context The bandwidth (b=) line is not necessarily redundant in the ATM context
since, in some applications, it can be used to convey application-level
information which does not map directly into the atmFtrfcDesc and
atmBtrfcDesc media attribute lines. For instance, the 'b' line can be used
Rajesh Kumar, Mohamed Mostafa. 9 Rajesh Kumar, Mohamed Mostafa. 9
since, in some applications, it can be used to convey application-level
information which does not map directly into the atmTrfcDesc
media attribute line. For instance, the 'b' line can be used
in SDP descriptors in RTSP commands to describe content bandwidth. in SDP descriptors in RTSP commands to describe content bandwidth.
The encryption key line (k=) can be used The encryption key line (k=) can be used
to indicate an encryption key for the bearer, and a method to to indicate an encryption key for the bearer, and a method to
obtain the key. At present, the encryption of ATM and AAL2 bearers obtain the key. At present, the encryption of ATM and AAL2 bearers
has not been conventionalized, unlike the encryption of RTP payloads. has not been conventionalized, unlike the encryption of RTP payloads.
Nor has the authentication or encryption of ATM or AAL2 bearer signaling. Nor has the authentication or encryption of ATM or AAL2 bearer signaling.
In the ATM and AAL2 contexts, the term 'bearer' can include 'bearer In the ATM and AAL2 contexts, the term 'bearer' can include 'bearer
signaling' as well as 'bearer payloads'. signaling' as well as 'bearer payloads'.
skipping to change at line 618 skipping to change at line 612
the <address> refers to the address of the node building the SDP the <address> refers to the address of the node building the SDP
description. When this description is forwarded to another node, it still description. When this description is forwarded to another node, it still
contains the original node's address. When the media gateway contains the original node's address. When the media gateway
controller builds part or all of the SDP description, the local descriptor controller builds part or all of the SDP description, the local descriptor
contains the address of the local node, while the contains the address of the local node, while the
remote descriptor contains the address of the remote node. remote descriptor contains the address of the remote node.
If the <address> and/or <addressType> are irrelevant or are If the <address> and/or <addressType> are irrelevant or are
known by other means, they can be set to a "$" or a "-", as described known by other means, they can be set to a "$" or a "-", as described
below. below.
Additionally, in all contexts, the 'm' line can have an ATM address in the
Rajesh Kumar, Mohamed Mostafa. 12 Rajesh Kumar, Mohamed Mostafa. 12
Additionally, in all contexts, the 'm' line can have an ATM address in the
<virtualConnectionId> subparameter which, if present, is the <virtualConnectionId> subparameter which, if present, is the
remote address if the 'c' line address is local, and vice versa. remote address if the 'c' line address is local, and vice versa.
For ATM networks, the <addressType> can be NSAP, E164 or GWID (ALIAS). For ATM networks, the <addressType> can be NSAP, E164 or GWID (ALIAS).
For ATM networks, the <address> syntax depends on the syntax of For ATM networks, the <address> syntax depends on the syntax of
the <addressType>. SDP parsers should check the consistency the <addressType>. SDP parsers should check the consistency
of <addressType> with <address>. of <addressType> with <address>.
NSAP: If the addressType is NSAP, the address is expressed in NSAP: If the addressType is NSAP, the address is expressed in
the standard dotted hex form. This is a string of 40 hex digits, the standard dotted hex form. This is a string of 40 hex digits,
with dots after the 2nd, 6th, 10th, 14th, 18th, 22nd, 26th, 30th, with dots after the 2nd, 6th, 10th, 14th, 18th, 22nd, 26th, 30th,
34th and 38th digits. The last octet of the NSAP address is the 34th and 38th digits. The last octet of the NSAP address is the
'selector' field that is available for non-standard use. An example 'selector' field that is available for non-standard use. An example
of a c line with an NSAP address is: of a c line with an NSAP address is:
c=ATM NSAP 47.0091.8100.0000.0060.3e64.fd01.0060.3e64.fd01.00 c=ATM NSAP 47.0091.8100.0000.0060.3e64.fd01.0060.3e64.fd01.00
A "0x" prefix shall not be used in this case since this is always in A "0x" prefix shall not be used in this case since this is always in
hexadecimal format. hexadecimal format.
E164: If the addressType is E164, the address is expressed as E164: If the addressType is E164, the address is expressed as
a decimal number with up to 15 digits. For example: a decimal number with up to 15 digits. For example:
c=ATM E164 9738294382 c=ATM E164 9738294382
skipping to change at line 657 skipping to change at line 650
There is a disparity between the ATM forum and the ITU There is a disparity between the ATM forum and the ITU
in the use of E.164 numbers for ATM addressing. The ATM forum (e.g. UNI in the use of E.164 numbers for ATM addressing. The ATM forum (e.g. UNI
Signaling 4.0) allows only International Format E.164 numbers, while Signaling 4.0) allows only International Format E.164 numbers, while
the ITU (e.g. Q.2931) allows private numbering plans. Since the goal the ITU (e.g. Q.2931) allows private numbering plans. Since the goal
of this SDP specification is to interoperate with all bearer signaling of this SDP specification is to interoperate with all bearer signaling
protocols, it allows the use of numbers that do not conform to the protocols, it allows the use of numbers that do not conform to the
E.164 International Format. However, to maximize overall consistency, E.164 International Format. However, to maximize overall consistency,
network administrators can restrict the provisioning of numbers to the network administrators can restrict the provisioning of numbers to the
E.164 International Format. E.164 International Format.
GWID (ALIAS): If the addressType is GWID meaning that the address is a GWID (ALIAS): If the addressType is GWID, it means that the address is a
Gateway Identifier or Node Alias. This may or may not be globally unique. Gateway Identifier or Node Alias. This may or may not be globally unique.
In this case, the address is expressed as alphanumeric string In this format, the address is expressed as an alphanumeric string
("A"-"Z", "a"-"z", "0" - "9",".","-","_"). For example: ("A"-"Z", "a"-"z", "0" - "9",".","-","_"). For example:
c=ATM GWID officeABCmgx101vism12 c=ATM GWID officeABCmgx101vism12
Since these SDP conventions can be used for more than gateways, the Since these SDP conventions can be used for more than gateways, the
string "ALIAS" can be used instead of "GWID" in the 'c' line. Thus, string "ALIAS" can be used instead of "GWID" in the 'c' line. Thus,
the example above is equivalent to: the example above is equivalent to:
c=ATM ALIAS officeABCmgx101vism12 c=ATM ALIAS officeABCmgx101vism12
An example of a GWID (ALIAS)is the CLLI code used for telecom An example of a GWID (ALIAS)is the CLLI code used for telecom
equipment. For all practical purposes, it should be adequate for the
Rajesh Kumar, Mohamed Mostafa. 13 Rajesh Kumar, Mohamed Mostafa. 13
equipment. For all practical purposes, it should be adequate for the
GWID (ALIAS) to be a variable length string with a maximum size of 32 GWID (ALIAS) to be a variable length string with a maximum size of 32
characters. characters.
The connection information line is always present in an SDP session The connection information line is always present in an SDP session
descriptor. However, each of the parameters on this line can be wildcarded descriptor. However, each of the parameters on this line can be wildcarded
to a "$" or a "-", independently of whether other parameters on this line to a "$" or a "-", independently of whether other parameters on this line
are wildcarded or not. Not all syntactically legal wildcard combinations are wildcarded or not. Not all syntactically legal wildcard combinations
are meaningful in a particular application. are meaningful in a particular application.
Examples of meaningful wildcard combinations in the ATM context are: Examples of meaningful wildcard combinations in the ATM context are:
skipping to change at line 725 skipping to change at line 718
t= <startTime> <stopTime> t= <startTime> <stopTime>
Per Ref. [49], NTP time stamps use a 32 bit unsigned Per Ref. [49], NTP time stamps use a 32 bit unsigned
representation of seconds, and a 32 bit unsigned representation of representation of seconds, and a 32 bit unsigned representation of
fractional seconds. For ATM-based sessions, the <startTime>parameter can fractional seconds. For ATM-based sessions, the <startTime>parameter can
be made equal to the NTP timestamp referring to the moment when be made equal to the NTP timestamp referring to the moment when
the SDP session descriptor was created. It can also be set to 0 the SDP session descriptor was created. It can also be set to 0
indicating its irrelevance. If it made equal to the NTP indicating its irrelevance. If it made equal to the NTP
timestamp in seconds, the fractional part of the NTP timestamp is omitted. timestamp in seconds, the fractional part of the NTP timestamp is omitted.
When equated to the integer part of an NTP timestamp, the <startTime> When equated to the integer part of an NTP timestamp, the <startTime>
field is 10 digits wide. This is more restricted than [1], which
Rajesh Kumar, Mohamed Mostafa. 14 Rajesh Kumar, Mohamed Mostafa. 14
field is 10 digits wide. This is more restricted than [1], which
allows unlimited size. As in [1], the most significant digit is allows unlimited size. As in [1], the most significant digit is
non-zero when an NTP timestamp is used. non-zero when an NTP timestamp is used.
The <stopTime> parameter is set to 0 for ATM-based SDP descriptors. The <stopTime> parameter is set to 0 for ATM-based SDP descriptors.
5.5 Media Information Line for ATM connections 5.5 Media Information Line for ATM connections
The general format of the media information line adapted for AAL1 The general format of the media information line adapted for AAL1
and AAL5 applications is: and AAL5 applications is:
skipping to change at line 779 skipping to change at line 772
The <virtualConnectionId> in AAL2 applications can be in one of the The <virtualConnectionId> in AAL2 applications can be in one of the
following formats: following formats:
* <ex_vcci>/<ex_cid> * <ex_vcci>/<ex_cid>
* <addressType>-<address>/<ex_vcci>/<ex_cid> * <addressType>-<address>/<ex_vcci>/<ex_cid>
* <address>/<ex_vcci>/<ex_cid> * <address>/<ex_vcci>/<ex_cid>
* <ex_bcg>/<ex_vcci>/<ex_cid> * <ex_bcg>/<ex_vcci>/<ex_cid>
* <ex_portId>/<ex_vpi>/<ex_vci>/<ex_cid> * <ex_portId>/<ex_vpi>/<ex_vci>/<ex_cid>
* <ex_bcg>/<ex_vpi>/<ex_vci>/<ex_cid> * <ex_bcg>/<ex_vpi>/<ex_vci>/<ex_cid>
* <ex_vpci>/<ex_vci>/<ex_cid>
Rajesh Kumar, Mohamed Mostafa. 15 Rajesh Kumar, Mohamed Mostafa. 15
* <ex_vpci>/<ex_vci>/<ex_cid>
* <addressType>-<address>/<ex_vpci>/<ex_vci>/<ex_cid> * <addressType>-<address>/<ex_vpci>/<ex_vci>/<ex_cid>
* <address>/<ex_vpci>/<ex_vci>/<ex_cid> * <address>/<ex_vpci>/<ex_vci>/<ex_cid>
Here, Here,
<ex_vcci> = VCCI-<vcci> <ex_vcci> = VCCI-<vcci>
<ex_vpci> = VPCI-<vpci> <ex_vpci> = VPCI-<vpci>
<ex_bcg> = BCG-<bcg> <ex_bcg> = BCG-<bcg>
<ex_portId> = PORT-<portId> <ex_portId> = PORT-<portId>
<ex_vpi> = VPI-<vpi> <ex_vpi> = VPI-<vpi>
<ex_vci> = VCI-<vci> <ex_vci> = VCI-<vci>
skipping to change at line 824 skipping to change at line 817
Q.2931 [Ref. 15]. The <vpci> is similar to the <vpi>,except for its Q.2931 [Ref. 15]. The <vpci> is similar to the <vpi>,except for its
width and the fact that it retains its value across VP crossconnects. width and the fact that it retains its value across VP crossconnects.
In some applications, the size of the <vpci> is the same as the size of In some applications, the size of the <vpci> is the same as the size of
the <vpi> (8 or 12 bits). In this case, the most significant 8 or 4 bits the <vpi> (8 or 12 bits). In this case, the most significant 8 or 4 bits
are ignored. are ignored.
The <vcci> is a 16-bit field defined in ITU Recommendation Q.2941.2 [32]. The <vcci> is a 16-bit field defined in ITU Recommendation Q.2941.2 [32].
The <vcci> is similar to the <vci>, except for the fact that it retains The <vcci> is similar to the <vci>, except for the fact that it retains
its value across VC crossconnects. its value across VC crossconnects.
Since <vpci> and <vcci> values are unique between a pair of nodes, they In general, <vpci> and <vcci> values are unique between a
need to be qualified, at any node, by the ATM address of the remote node. pair of nodes. When they are unique between a pair of nodes
but not unique within a network, they need to be qualified,
at any node, by the ATM address of the remote node.
These parameters can be pre-provisioned or signaled. When signaled, the These parameters can be pre-provisioned or signaled. When signaled, the
<vpci> is encapsulated in the connection identifier information element of <vpci> is encapsulated in the connection identifier information element of
SVC signaling messages. The <vcci> is encapsulated in the Generic SVC signaling messages. The <vcci> is encapsulated in the Generic
Information Transport (GIT) information element of SVC signaling messages. Information Transport (GIT) information element of SVC signaling messages.
In an ATM node pair, either node can assign <vcci> values and signal it to In an ATM node pair, either node can assign <vcci> values and signal it to
Rajesh Kumar, Mohamed Mostafa. 16
the other end via SVC signaling. A glare avoidance scheme is defined in [32] the other end via SVC signaling. A glare avoidance scheme is defined in [32]
and [44].This mechanism works in SVC applications. A different glare and [44].This mechanism works in SVC applications. A different glare
avoidance technique is needed when a pool of existing PVCs/SPVCs is avoidance technique is needed when a pool of existing PVCs/SPVCs is
Rajesh Kumar, Mohamed Mostafa. 16
dynamically assigned to calls. One such scheme for glare reduction is the dynamically assigned to calls. One such scheme for glare reduction is the
assignment of <vcci> values from different ends of the <vcci> range, using assignment of <vcci> values from different ends of the <vcci> range, using
the lowest or highest available value as applicable. the lowest or highest available value as applicable.
When <vpci> and <vcci> values are pre-provisioned, administrations have the When <vpci> and <vcci> values are pre-provisioned, administrations have the
option of provisioning them uniquely in a network or in a subnet. In this option of provisioning them uniquely in a network. In this
case, the ATM address of the far end is not needed to qualify these case, the ATM address of the far end is not needed to qualify these
parameters. parameters.
In the AAL2 context, the definition of a VCC implies that there is no In the AAL2 context, the definition of a VCC implies that there is no
CID-level switching between its ends. If either end can assign <cid> CID-level switching between its ends. If either end can assign <cid>
values, then a glare reduction mechanism is needed. One such scheme for values, then a glare reduction mechanism is needed. One such scheme for
glare reduction is the assignment of <cid> values from different ends glare reduction is the assignment of <cid> values from different ends
of the <cid> range, using the lowest or highest available value as of the <cid> range, using the lowest or highest available value as
applicable. applicable.
skipping to change at line 882 skipping to change at line 878
Examples of wildcarding the <virtualConnectionId> in the AAL1 and AAL5 Examples of wildcarding the <virtualConnectionId> in the AAL1 and AAL5
contexts are: $, VCCI-$, BCG-100/VPI-20/VCI-$. Examples of contexts are: $, VCCI-$, BCG-100/VPI-20/VCI-$. Examples of
wildcarding the <virtualConnectionId> in the AAL2 context are: $, wildcarding the <virtualConnectionId> in the AAL2 context are: $,
VCCI-40/CID-$, BCG-100/VPI-20/VCI-120/CID-$, NSAP-$/VCCI-$/CID-$, VCCI-40/CID-$, BCG-100/VPI-20/VCI-120/CID-$, NSAP-$/VCCI-$/CID-$,
$/VCCI-$/CID-$. $/VCCI-$/CID-$.
It is also permissible to set the entire <virtualConnectionId> parameter It is also permissible to set the entire <virtualConnectionId> parameter
to a "-" indicating its irrelevance. to a "-" indicating its irrelevance.
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5.5.2 The Transport Parameter 5.5.2 The Transport Parameter
The <transport> parameter indicates the method used to encapsulate the The <transport> parameter indicates the method used to encapsulate the
service payload. These methods are not defined in this document, which service payload. These methods are not defined in this document, which
refers to existing ATMF and ITU-T standards, which, in turn, might refers to existing ATMF and ITU-T standards, which, in turn, might
refer to other standards. For ATM applications, the following refer to other standards. For ATM applications, the following
Rajesh Kumar, Mohamed Mostafa. 17
<transport> values are defined: <transport> values are defined:
Table 1: List of Transport Parameter values used in SDP in the ATM context Table 1: List of Transport Parameter values used in SDP in the ATM context
+---------------------------------------------------------------------+ +---------------------------------------------------------------------+
| | Controlling Document for | | | Controlling Document for |
| Transport | Encapsulation of Service Payload | | Transport | Encapsulation of Service Payload |
+------------------------+--------------------------------------------+ +------------------------+--------------------------------------------+
| AAL1/ATMF | af-vtoa-0078.000 [7] | | AAL1/ATMF | af-vtoa-0078.000 [7] |
+------------------------+--------------------------------------------+ +------------------------+--------------------------------------------+
| AAL1/ITU | ITU-T H.222.1 [51] | | AAL1/ITU | ITU-T H.222.1 [51] |
skipping to change at line 937 skipping to change at line 933
directly over AAL5 per [45] can be indicated explicitly via the aalApp directly over AAL5 per [45] can be indicated explicitly via the aalApp
media attribute. media attribute.
A value of "AAL1/custom", "AAL2/custom" or "AAL5/custom" for the A value of "AAL1/custom", "AAL2/custom" or "AAL5/custom" for the
<transport> parameter can indicate non-standard or semi-standard <transport> parameter can indicate non-standard or semi-standard
encapsulation schemes defined by a corporation or a multi-vendor encapsulation schemes defined by a corporation or a multi-vendor
agreement. Since there is no standard administration of this agreement. Since there is no standard administration of this
convention, care should be taken to preclude inconsistencies convention, care should be taken to preclude inconsistencies
within the scope of a deployment. within the scope of a deployment.
Rajesh Kumar, Mohamed Mostafa. 18
The use of <transport> values "AAL1/<corporateName>", The use of <transport> values "AAL1/<corporateName>",
"AAL2/<corporateName>", "AAL5/<corporateName>", "AAL1/IEEE:<oui>", "AAL2/<corporateName>", "AAL5/<corporateName>", "AAL1/IEEE:<oui>",
"AAL2/IEEE:<oui>" and "AAL5/IEEE:<oui>" is similar. These indicate "AAL2/IEEE:<oui>" and "AAL5/IEEE:<oui>" is similar. These indicate
non-standard transport mechanisms or AAL2 profiles which should non-standard transport mechanisms or AAL2 profiles which should
be used consistently within the scope of an application or deployment. be used consistently within the scope of an application or deployment.
Rajesh Kumar, Mohamed Mostafa. 18
The parameter <corporateName> is the registered, globally unique name The parameter <corporateName> is the registered, globally unique name
of a corporation(e.g. Cisco, Telcordia etc.). The parameter <oui> of a corporation(e.g. Cisco, Telcordia etc.). The parameter <oui>
is the hex representation of a three-octet field identical to the OUI is the hex representation of a three-octet field identical to the OUI
maintained by the IEEE. Since this is always represented in hex, the "0x" maintained by the IEEE. Since this is always represented in hex, the "0x"
prefix shall not be used. Leading zeros can be omitted. For prefix shall not be used. Leading zeros can be omitted. For
example, "IEEE:00000C" and "IEEE:C" both refer to example, "IEEE:00000C" and "IEEE:C" both refer to
Cisco Systems, Inc. Cisco Systems, Inc.
5.5.3 The Format List for AAL1 and AAL5 applications 5.5.3 The Format List for AAL1 and AAL5 applications
skipping to change at line 987 skipping to change at line 982
In the AAL2 context, the <format list> is a list of AAL2 profile In the AAL2 context, the <format list> is a list of AAL2 profile
types: types:
<profile#1> <profile#2>...<profile#n> <profile#1> <profile#2>...<profile#n>
In most applications, the ordering of profiles implies In most applications, the ordering of profiles implies
a preference (preferred profiles before less favored ones). a preference (preferred profiles before less favored ones).
The <profile> parameter is expressed as a decimal number in the The <profile> parameter is expressed as a decimal number in the
range 1-255. range 1-255.
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5.5.5 Media information line construction 5.5.5 Media information line construction
Using the parameter definitions above, the 'm' for AAL1-based audio Using the parameter definitions above, the 'm' for AAL1-based audio
media can be constructed as follows: media can be constructed as follows:
m=audio <virtualConnectionId> AAL1/ATMF <payloadType#1> m=audio <virtualConnectionId> AAL1/ATMF <payloadType#1>
<payloadType#2>...<payloadType #n> <payloadType#2>...<payloadType #n>
Rajesh Kumar, Mohamed Mostafa. 19
Note that only those payload types, whether statically mapped or Note that only those payload types, whether statically mapped or
dynamically assigned, that are consistent with af-vtoa-78 [7] can be used dynamically assigned, that are consistent with af-vtoa-78 [7] can be used
in this construction. in this construction.
Backwards compatibility note: The transport value "AAL1/AVP" used in Backwards compatibility note: The transport value "AAL1/AVP" used in
previous versions of this document should be considered equivalent to previous versions of this document should be considered equivalent to
the value "AAL1/ATMF" defined above. "AAL1/AVP" is unsuitable because the value "AAL1/ATMF" defined above. "AAL1/AVP" is unsuitable because
the AVP profile is closely tied to RTP. the AVP profile is closely tied to RTP.
An example 'm' line use for audio media over AAL1 is: An example 'm' line use for audio media over AAL1 is:
skipping to change at line 1041 skipping to change at line 1036
implies that any VCI on VPI= 6 of trunk port #2 may be used. The identities implies that any VCI on VPI= 6 of trunk port #2 may be used. The identities
of the terms in the virtual connection ID are implicit in the application of the terms in the virtual connection ID are implicit in the application
context. The audio media on this VCC is encapsulated according to ITU-T context. The audio media on this VCC is encapsulated according to ITU-T
H.222.1 [51]. The encodings to be used are either ITU-T G.722 or ITU-T H.222.1 [51]. The encodings to be used are either ITU-T G.722 or ITU-T
G.728 (LD-CELP), in preferential order. G.728 (LD-CELP), in preferential order.
The 'm' for AAL5-based H.323 Annex C audio [45] can be constructed as The 'm' for AAL5-based H.323 Annex C audio [45] can be constructed as
follows: follows:
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m=audio <virtualConnectionId> RTP/AVP <payloadType#1> m=audio <virtualConnectionId> RTP/AVP <payloadType#1>
<payloadType#2>...<payloadType #n> <payloadType#2>...<payloadType #n>
For example: For example:
m=audio PORT-9/VPI-3/VCI-$ RTP/AVP 2 96 m=audio PORT-9/VPI-3/VCI-$ RTP/AVP 2 96
a=rtpmap:96 X-G727-32 a=rtpmap:96 X-G727-32
a=aalType:AAL5 a=aalType:AAL5
Rajesh Kumar, Mohamed Mostafa. 20
a=aalApp:itu_h323c - - a=aalApp:itu_h323c - -
implies that any VCI on VPI= 3 of trunk port #9 may be used. This VC implies that any VCI on VPI= 3 of trunk port #9 may be used. This VC
encapsulates RTP packets directly on AAL5 per [45]. The 'rtpmap' (rather encapsulates RTP packets directly on AAL5 per [45]. The 'rtpmap' (rather
than the 'atmmap') attribute is used to dynamically map the payload type than the 'atmmap') attribute is used to dynamically map the payload type
of 96 into the codec name X-G727-32 (Table 2). This name represents 32 of 96 into the codec name X-G727-32 (Table 2). This name represents 32
kbps EADPCM. kbps EADPCM.
The 'm' line for AAL5-based video media can be constructed as follows: The 'm' line for AAL5-based video media can be constructed as follows:
skipping to change at line 1094 skipping to change at line 1088
a <format list>. This is because it is possible to consider definitions a <format list>. This is because it is possible to consider definitions
from multiple sources (ATMF, ITU and non-standard documents) when selecting from multiple sources (ATMF, ITU and non-standard documents) when selecting
AAL2 profile to be bound to a connection. AAL2 profile to be bound to a connection.
In most applications, the ordering of profiles implies a preference In most applications, the ordering of profiles implies a preference
(preferred profiles before less favored ones). Therefore, there can be (preferred profiles before less favored ones). Therefore, there can be
multiple instances of the same <transport> value in the same 'm' line. multiple instances of the same <transport> value in the same 'm' line.
An example 'm' line use for audio media over AAL2 is: An example 'm' line use for audio media over AAL2 is:
Rajesh Kumar, Mohamed Mostafa. 21
m=audio VCCI-27/CID-19 AAL2/ITU 7 AAL2/custom 100 AAL2/ITU 1 m=audio VCCI-27/CID-19 AAL2/ITU 7 AAL2/custom 100 AAL2/ITU 1
This indicates the use of CID #19 on VCCI #27 to carry audio. It provides This indicates the use of CID #19 on VCCI #27 to carry audio. It provides
a preferential list of profiles for this connection: profile AAL2/ITU 7 a preferential list of profiles for this connection: profile AAL2/ITU 7
defined in [13], AAL2/custom 100 defined in an application-specific or defined in [13], AAL2/custom 100 defined in an application-specific or
interoperability document and profile AAL2/ITU 1 defined in [13]. interoperability document and profile AAL2/ITU 1 defined in [13].
Rajesh Kumar, Mohamed Mostafa. 21
Another example of the use of the 'm' line use for audio media over AAL2 Another example of the use of the 'm' line use for audio media over AAL2
is: is:
m=audio VCCI-$/CID-$ AAL2/ATMF 6 8 m=audio VCCI-$/CID-$ AAL2/ATMF 6 8
This indicates that any AAL2 CID may be used, subject to any applicable This indicates that any AAL2 CID may be used, subject to any applicable
glare avoidance/reduction rules. The profiles that can be bound to this glare avoidance/reduction rules. The profiles that can be bound to this
connection are AAL2/ATMF 6 defined in af-vtoa-0113.000 [44] and AAL2/ATMF 8 connection are AAL2/ATMF 6 defined in af-vtoa-0113.000 [44] and AAL2/ATMF 8
defined in af-vmoa-0145.000 [52]. These sources use non-overlapping defined in af-vmoa-0145.000 [52]. These sources use non-overlapping
profile number ranges. The profiles they define fall under the <transport> profile number ranges. The profiles they define fall under the <transport>
skipping to change at line 1146 skipping to change at line 1140
In another example application, the'aal2sscs3662' attribute can indicate In another example application, the'aal2sscs3662' attribute can indicate
<faxDemod> = "on" and any other competing options as "off", and the <faxDemod> = "on" and any other competing options as "off", and the
<aalType> attribute can indicate AAL2. Thus: <aalType> attribute can indicate AAL2. Thus:
m=audio VCCI-123/CID-5 - - m=audio VCCI-123/CID-5 - -
a=aalType:AAL2 a=aalType:AAL2
a=aal2sscs3662:audio off off on off on off off off - - - a=aal2sscs3662:audio off off on off on off off off - - -
Besides indicating an audio medium, a VCCI of 123 and a CID of 5, Besides indicating an audio medium, a VCCI of 123 and a CID of 5,
Rajesh Kumar, Mohamed Mostafa. 22
the 'm' line indicates an unspecified profile. The media attribute lines the 'm' line indicates an unspecified profile. The media attribute lines
indicate an adaptation layer of AAL2, and the use of the audio SAP [13] indicate an adaptation layer of AAL2, and the use of the audio SAP [13]
to carry demodulated facsimile. to carry demodulated facsimile.
The media information line for "data" media has one of the following The media information line for "data" media has one of the following
the following formats: the following formats:
m=data <virtualConnectionId> - - m=data <virtualConnectionId> - -
Rajesh Kumar, Mohamed Mostafa. 22
m=data - - - m=data - - -
The data could be circuit emulation data carried over AAL1 or AAL2, The data could be circuit emulation data carried over AAL1 or AAL2,
or packet data carried over AAL5. Media attribute lines, rather than or packet data carried over AAL5. Media attribute lines, rather than
the 'm' line, are used to indicate the adaptation type for the data the 'm' line, are used to indicate the adaptation type for the data
media. Examples of the representation of data media are listed below. media. Examples of the representation of data media are listed below.
m=data PORT-7/VPI-6/VCI-$ - - m=data PORT-7/VPI-6/VCI-$ - -
a=aalApp:AAL5_SSCOP- - a=aalApp:AAL5_SSCOP- -
skipping to change at line 1201 skipping to change at line 1195
mode data as an "audio" codec. If this is done, the codec types used mode data as an "audio" codec. If this is done, the codec types used
are X-CCD or X-CCD-CAS. These encoding names are dynamically are X-CCD or X-CCD-CAS. These encoding names are dynamically
mapped into payload types through the 'atmmap' attribute. For example: mapped into payload types through the 'atmmap' attribute. For example:
m=audio VCCI-27 AAL1/AVP 98 m=audio VCCI-27 AAL1/AVP 98
a=atmmap:98 X-CCD a=atmmap:98 X-CCD
a=sbc:6 a=sbc:6
implies that AAL1 VCCI=27 is used for 6 x 64 transmission. implies that AAL1 VCCI=27 is used for 6 x 64 transmission.
Rajesh Kumar, Mohamed Mostafa. 23
In the AAL2 context, the X-CCD codec can be assigned a profile In the AAL2 context, the X-CCD codec can be assigned a profile
type and number. Even though it is not possible to construct type and number. Even though it is not possible to construct
a profile table as described in ITU I.366.2 for this "codec", a profile table as described in ITU I.366.2 for this "codec",
it is preferable to adopt the common AAL2 profile convention in its it is preferable to adopt the common AAL2 profile convention in its
case. An example AAL2 profile mapping for the X-CCD codec could case. An example AAL2 profile mapping for the X-CCD codec could
be as follows: be as follows:
Rajesh Kumar, Mohamed Mostafa. 23
PROFILE TYPE PROFILE NUMBER "CODEC" (ONLY ONE) PROFILE TYPE PROFILE NUMBER "CODEC" (ONLY ONE)
"custom" 200 X-CCD "custom" 200 X-CCD
The profile does not identify the number of subchannels ('n' in nx64). The profile does not identify the number of subchannels ('n' in nx64).
This is known by other means such as the 'sbc' media attribute line. This is known by other means such as the 'sbc' media attribute line.
For example, the media information line: For example, the media information line:
m=audio $ AAL2/custom 200 m=audio $ AAL2/custom 200
a=sbc:6 a=sbc:6
skipping to change at line 1252 skipping to change at line 1246
In attribute lines, subparameters that are meant to be left In attribute lines, subparameters that are meant to be left
unspecified are set to a "-". These are generally inapplicable or, if unspecified are set to a "-". These are generally inapplicable or, if
applicable, are known by other means such as provisioning. In some applicable, are known by other means such as provisioning. In some
cases, a media attribute line with all parameters set to "-" carries cases, a media attribute line with all parameters set to "-" carries
no information and should be preferably omitted. In other cases, no information and should be preferably omitted. In other cases,
such as the 'lij' media attribute line, the very presence of the such as the 'lij' media attribute line, the very presence of the
media attribute line conveys meaning. media attribute line conveys meaning.
There are no restrictions placed by rfc2327 [1] regarding the order There are no restrictions placed by rfc2327 [1] regarding the order
of 'a' lines with respect to other 'a' lines. However, these lines of 'a' lines with respect to other 'a' lines. However, these lines
Rajesh Kumar, Mohamed Mostafa. 24
must not contradict each other or the other SDP lines. Inconsistencies must not contradict each other or the other SDP lines. Inconsistencies
are not to be ignored and should be flagged as errors. Repeated media are not to be ignored and should be flagged as errors. Repeated media
attribute lines can carry additional information. These should not attribute lines can carry additional information. These should not
be inconsistent with each other. be inconsistent with each other.
Applications will selectively use the optional media attribute Applications will selectively use the optional media attribute
lines listed below. This is meant to be an exhaustive list for lines listed below. This is meant to be an exhaustive list for
describing the general attributes of ATM bearer networks. describing the general attributes of ATM bearer networks.
Rajesh Kumar, Mohamed Mostafa. 24
The base specification for SDP, rfc2327 [1], allows the definition The base specification for SDP, rfc2327 [1], allows the definition
of new attributes. In keeping with this spirit, some of the attributes of new attributes. In keeping with this spirit, some of the attributes
defined in this document can also be used in SDP descriptions of IP defined in this document can also be used in SDP descriptions of IP
and other non-ATM sessions. For example, the 'vsel', 'dsel' and 'fsel' and other non-ATM sessions. For example, the 'vsel', 'dsel' and 'fsel'
attributes defined below refer generically to codecs. These can be attributes defined below refer generically to codecs. These can be
used for service-specific codec negotiation and assignment in non-ATM used for service-specific codec negotiation and assignment in non-ATM
as well as ATM applications. as well as ATM applications.
SDP media attributes defined in this document for use in the ATM SDP media attributes defined in this document for use in the ATM
context are classified as: context are classified as:
skipping to change at line 1305 skipping to change at line 1300
* The 'fmtp' attribute used to designate format-specific * The 'fmtp' attribute used to designate format-specific
parameters. parameters.
5.6.1 ATM bearer connection attributes 5.6.1 ATM bearer connection attributes
The following is a summary list of the SDP media attributes that can The following is a summary list of the SDP media attributes that can
be used to describe ATM bearer connections. These are detailed in be used to describe ATM bearer connections. These are detailed in
subsequent subsections. subsequent subsections.
* The 'eecid' attribute. This stands for 'end-to-end connection * The 'eecid' attribute. This stands for 'end-to-end connection
Rajesh Kumar, Mohamed Mostafa. 25
identifier'. It provides a means of correlating service-level identifier'. It provides a means of correlating service-level
connections with underlying ATM bearer connections. connections with underlying ATM bearer connections.
In the Q.1901 [36] context, the eecid is synonymous with the In the Q.1901 [36] context, the eecid is synonymous with the
bnc-id (backbone network connection identifier). bnc-id (backbone network connection identifier).
* The 'aalType' attribute. This is used to indicate the nature * The 'aalType' attribute. This is used to indicate the nature
of the ATM adaptation layer (AAL). of the ATM adaptation layer (AAL).
Rajesh Kumar, Mohamed Mostafa. 25
* The 'capability' attribute, which indicates the ATM transfer * The 'capability' attribute, which indicates the ATM transfer
capability (ITU nomenclature), synonymous with the ATM Service capability (ITU nomenclature), synonymous with the ATM Service
Category (ATMF nomenclature). Category (ATMF nomenclature).
* The 'qosClass' attribute, which indicates the QoS class of the * The 'qosClass' attribute, which indicates the QoS class of the
ATM bearer connection. ATM bearer connection.
* The 'bcob' attribute, which indicates the broadband connection * The 'bcob' attribute, which indicates the broadband connection
oriented bearer class, and whether end-to-end timing is oriented bearer class, and whether end-to-end timing is
required. required.
* The 'stc' attribute, which indicates susceptibility to * The 'stc' attribute, which indicates susceptibility to
clipping. clipping.
* The 'upcc' attribute, which indicates the user plane connection * The 'upcc' attribute, which indicates the user plane connection
configuration. configuration.
* The 'atmQOSfparms' and 'atmQOSbparms' attributes, which are * The 'atmQOSparms' attribute, which is
used to describe certain key ATM QoS parameters in the forward used to describe certain key ATM QoS parameters.
and backward directions respectively.
* The 'atmFtrfcDesc' and 'atmBtrfcDesc' attributes, which are * The 'atmTrfcDesc' attribute, which is
used to describe ATM traffic descriptor parameters in the used to describe ATM traffic descriptor parameters.
forward and backward directions respectively.
* The 'abrFparms' and 'abrBparms' attributes, which are * The 'abrParms' attribute, which is
used to describe ABR-specific parameters in the used to describe ABR-specific parameters. These parameters
forward and backward directions respectively. These parameters
are per the UNI 4.0 signaling specification [5]. are per the UNI 4.0 signaling specification [5].
* The 'abrSetup' attribute, which is used to indicate the * The 'abrSetup' attribute, which is used to indicate the
ABR parameters needed during call/connection establishment. ABR parameters needed during call/connection establishment.
* The 'bearerType' attribute, which is used to indicate * The 'bearerType' attribute, which is used to indicate
whether the underlying bearer is an ATM PVC/SPVC, an ATM SVC, whether the underlying bearer is an ATM PVC/SPVC, an ATM SVC,
or an AAL2 CID connection within an existing ATM SVC/PVC/SPVC. or an AAL2 CID connection within an existing ATM SVC/PVC/SPVC.
* The 'lij' attribute, which is used to indicate the * The 'lij' attribute, which is used to indicate the
presence of a connection that uses the Leaf-initiated-join presence of a connection that uses the Leaf-initiated-join
capability described in UNI 4.0 [5], and to optionally capability described in UNI 4.0 [5], and to optionally
describe parameters associated with this capability. describe parameters associated with this capability.
* The 'anycast' attribute, which is used to * The 'anycast' attribute, which is used to
indicate the applicability of the anycast function described indicate the applicability of the anycast function described
in UNI 4.0 [5], and to optionally qualify it with certain in UNI 4.0 [5], and to optionally qualify it with certain
parameters. parameters.
Rajesh Kumar, Mohamed Mostafa. 26
* The 'cache' attribute, which is used to enable * The 'cache' attribute, which is used to enable
SVC caching and to specify an inactivity timer for SVC release. SVC caching and to specify an inactivity timer for SVC release.
* The 'bearerSigIE' attribute, which can be used to represent * The 'bearerSigIE' attribute, which can be used to represent
ITU Q-series information elements in bit-map form. This is useful ITU Q-series information elements in bit-map form. This is useful
Rajesh Kumar, Mohamed Mostafa. 26
in describing parameters that are not closely coupled to the in describing parameters that are not closely coupled to the
ATM and AAL layers. Examples are the B-HLI and B-LLI IEs specified ATM and AAL layers. Examples are the B-HLI and B-LLI IEs specified
in ITU Q.2931 [15], and the user-to-user information in ITU Q.2931 [15], and the user-to-user information
element described in ITU Q.2957 [48]. element described in ITU Q.2957 [48].
5.6.1.1 The 'eecid' attribute 5.6.1.1 The 'eecid' attribute
The 'eecid' attribute is synonymous with the 4-byte'bnc-id' The 'eecid' attribute is synonymous with the 4-byte'bnc-id'
parameter used by T1SI, the ATM forum and the ITU (Q.1901) parameter used by T1SI, the ATM forum and the ITU (Q.1901)
standardization effort. The term 'eecid' stands for 'end-to-end standardization effort. The term 'eecid' stands for 'end-to-end
skipping to change at line 1416 skipping to change at line 1408
The value of the eecid attribute values needs to be unique within The value of the eecid attribute values needs to be unique within
the node terminating the SVC set-up but not across multiple the node terminating the SVC set-up but not across multiple
nodes. Hence, the SVC-terminating gateway has complete control nodes. Hence, the SVC-terminating gateway has complete control
over using and releasing values of this parameter. The eecid over using and releasing values of this parameter. The eecid
attribute is used to correlate, one-to-one, received bearer set-up attribute is used to correlate, one-to-one, received bearer set-up
requests with service-level call control signaling. requests with service-level call control signaling.
Within an SDP session description, the eecid attribute is used as Within an SDP session description, the eecid attribute is used as
follows: follows:
Rajesh Kumar, Mohamed Mostafa. 27
a=eecid:<eecid> a=eecid:<eecid>
where <eecid> consists of up to 8 hex digits (equivalent to 4 where <eecid> consists of up to 8 hex digits (equivalent to 4
Rajesh Kumar, Mohamed Mostafa. 27
octets). Since this is always represented in hex, the "0x" octets). Since this is always represented in hex, the "0x"
prefix shall not be used. prefix shall not be used.
Within the text representation of the <eecid> parameter, hex digits Within the text representation of the <eecid> parameter, hex digits
to the left are more significant than hex digits to the right to the left are more significant than hex digits to the right
(Section 2.2). (Section 2.2).
This SDP document does not specify how the eecid (synonymous This SDP document does not specify how the eecid (synonymous
with bnc-id) is to be communicated through bearer signaling with bnc-id) is to be communicated through bearer signaling
(Q.931, UNI, PNNI, AINI, IISP, proprietary signaling equivalent, (Q.931, UNI, PNNI, AINI, IISP, proprietary signaling equivalent,
skipping to change at line 1468 skipping to change at line 1459
terminates. Since the eecid space is large enough, it is not terminates. Since the eecid space is large enough, it is not
necessary to release it as soon as possible. necessary to release it as soon as possible.
5.6.1.2 The 'aalType' attribute 5.6.1.2 The 'aalType' attribute
When present, the 'aalType' attribute is used to indicate When present, the 'aalType' attribute is used to indicate
the ATM adaptation layer. If this information is redundant the ATM adaptation layer. If this information is redundant
with the 'm' line, it can be omitted. The format of the with the 'm' line, it can be omitted. The format of the
'aalType' media attribute line is as follows: 'aalType' media attribute line is as follows:
Rajesh Kumar, Mohamed Mostafa. 28
a=aalType: <aalType> a=aalType: <aalType>
Here, <aalType> can take on the following string values: Here, <aalType> can take on the following string values:
"AAL1", "AAL1_SDT", "AAL1_UDT", "AAL2", "AAL3/4", "AAL5" "AAL1", "AAL1_SDT", "AAL1_UDT", "AAL2", "AAL3/4", "AAL5"
and "USER_DEFINED_AAL". Note that "AAL3/4" and "USER DEFINED AAL" and "USER_DEFINED_AAL". Note that "AAL3/4" and "USER DEFINED AAL"
Rajesh Kumar, Mohamed Mostafa. 28
are not addressed in this document. are not addressed in this document.
5.6.1.3 The 'capability' attribute 5.6.1.3 The 'capability' attribute
When present, the 'capability' attribute indicates the ATM Transfer When present, the 'capability' attribute indicates the ATM Transfer
Capability described in ITU I.371 [28], equivalent to the ATM Service Capability described in ITU I.371 [28], equivalent to the ATM Service
Category described in the UNI 4.1 Traffic Management specification [6]. Category described in the UNI 4.1 Traffic Management specification [6].
The 'capability' media attribute line is structured in one of The 'capability' media attribute line is structured in one of
the following ways: the following ways:
skipping to change at line 1522 skipping to change at line 1512
"CBR"/"DBR" 1 Voiceband signal transport "CBR"/"DBR" 1 Voiceband signal transport
(ITU G.711, G.722, I.363) (ITU G.711, G.722, I.363)
"CBR"/"DBR" 2 Circuit transport (ITU I.363) "CBR"/"DBR" 2 Circuit transport (ITU I.363)
"CBR"/"DBR" 4 High-quality audio signal transport "CBR"/"DBR" 4 High-quality audio signal transport
(ITU I.363) (ITU I.363)
"CBR"/"DBR" 5 Video signal transport (ITU I.363) "CBR"/"DBR" 5 Video signal transport (ITU I.363)
Note that [15] does not define a <subtype> value of 3. Note that [15] does not define a <subtype> value of 3.
For other values of the <asc> and <atc> parameters, the following For other values of the <asc> and <atc> parameters, the following
values can be assigned to the <subtype> field, based on [6] and [28].
Rajesh Kumar, Mohamed Mostafa. 29 Rajesh Kumar, Mohamed Mostafa. 29
values can be assigned to the <subtype> field, based on [6] and [28].
<asc>/<atc> <subtype> Meaning <asc>/<atc> <subtype> Meaning
nrt-VBR 1 nrt-VBR.1 nrt-VBR 1 nrt-VBR.1
nrt-VBR 2 nrt-VBR.2 nrt-VBR 2 nrt-VBR.2
nrt-VBR 3 nrt-VBR.3 nrt-VBR 3 nrt-VBR.3
rt-VBR 1 rt-VBR.1 rt-VBR 1 rt-VBR.1
rt-VBR 2 rt-VBR.2 rt-VBR 2 rt-VBR.2
rt-VBR 3 rt-VBR.3 rt-VBR 3 rt-VBR.3
UBR 1 UBR.1 UBR 1 UBR.1
UBR 2 UBR.2 UBR 2 UBR.2
skipping to change at line 1572 skipping to change at line 1563
0 Default QoS 0 Default QoS
1 Stringent 1 Stringent
2 Tolerant 2 Tolerant
3 Bi-level 3 Bi-level
4 Unbounded 4 Unbounded
5 Stringent bi-level 5 Stringent bi-level
5.6.1.5 The 'bcob' attribute 5.6.1.5 The 'bcob' attribute
When present, the 'bcob' attribute represents the broadband When present, the 'bcob' attribute represents the broadband
Rajesh Kumar, Mohamed Mostafa. 30
connection oriented bearer class defined in [5], [15] connection oriented bearer class defined in [5], [15]
and [33]. It can also be used to indicate whether end-to-end and [33]. It can also be used to indicate whether end-to-end
timing is required. timing is required.
Rajesh Kumar, Mohamed Mostafa. 30
The 'bcob' media attribute line is structured as follows: The 'bcob' media attribute line is structured as follows:
a=bcob:<bcob> <eetim> a=bcob:<bcob> <eetim>
Here, <bcob> is the decimal or hex representation of a 5-bit field. Here, <bcob> is the decimal or hex representation of a 5-bit field.
Currently, all values are unused and reserved with the following The following values are currently defined:
exceptions:
<bcob> Meaning <bcob> Meaning
0x01 BCOB-A 0x01 BCOB-A
0x03 BCOB-C 0x03 BCOB-C
0x05 Frame relaying bearer service 0x05 Frame relaying bearer service
0x10 BCOB-X 0x10 BCOB-X
0x18 BCOB-VP (transparent VP service) 0x18 BCOB-VP (transparent VP service)
The <eetim> parameter can be assigned a value of "on" or "off" The <eetim> parameter can be assigned a value of "on" or "off"
skipping to change at line 1617 skipping to change at line 1608
a=stc:<stc> a=stc:<stc>
Here, <stc> is the decimal equivalent of a 2-bit field. Currently, Here, <stc> is the decimal equivalent of a 2-bit field. Currently,
all values are unused and reserved with the following exceptions: all values are unused and reserved with the following exceptions:
<stc> value Binary Equivalent Meaning <stc> value Binary Equivalent Meaning
0 00 Not susceptible to clipping 0 00 Not susceptible to clipping
1 01 Susceptible to clipping 1 01 Susceptible to clipping
Rajesh Kumar, Mohamed Mostafa. 31
5.6.1.7 The 'upcc' attribute 5.6.1.7 The 'upcc' attribute
When present, the 'upcc' attribute represents the user plane When present, the 'upcc' attribute represents the user plane
connection configuration. The 'upcc' media attribute line is connection configuration. The 'upcc' media attribute line is
structured as follows: structured as follows:
a=upcc:<upcc> a=upcc:<upcc>
Here, <upcc> is the decimal equivalent of a 2-bit field. Currently, Here, <upcc> is the decimal equivalent of a 2-bit field. Currently,
all values are unused and reserved with the following exceptions: all values are unused and reserved with the following exceptions:
Rajesh Kumar, Mohamed Mostafa. 31
<upcc> value Binary Equivalent Meaning <upcc> value Binary Equivalent Meaning
0 00 Point to point 0 00 Point to point
1 01 Point to multipoint 1 01 Point to multipoint
5.6.1.8 The 'atmQOSfparms' and 'atmQOSbparms' attributes 5.6.1.8 The 'atmQOSparms' attribute
When present, the 'atmQOSfparms' and 'atmQOSbparms' When present, the 'atmQOSparms' attribute is used to describe
attributes are used to describe certain key ATM QoS parameters certain key ATM QoS parameters.
in the forward and backward directions respectively. See Section
2.3 for a definition of the terms 'forward' and 'backward'.
The 'atmQOSfparms' and 'atmQOSbparms' media attribute lines The 'atmQOSparms' media attribute line is structured as follows:
are structured as follows:
a=atmQOSfparms: <cdvType><acdv><ccdv><eetd><cmtd><aclr> a=atmQOSparms:<directionFlag><cdvType><acdv><ccdv><eetd><cmtd><aclr>
a=atmQOSbparms: <cdvType><acdv><ccdv><eetd><cmtd><aclr>
The <directionFlag> can be assigned the following string values: "f",
"b" and "fb". "f" and "b" indicate the forward and backward
directions respectively. "fb" refers to both directions (forward and
backward). Conventions for the forward and backward directions
are per section 2.3.
The <cdvType> parameter can take on the string values of The <cdvType> parameter can take on the string values of
"PP" and "2P". These refer to the peak-to-peak and two-point "PP" and "2P". These refer to the peak-to-peak and two-point
CDV as defined in UNI 4.0 [5] and ITU Q.2965.2 [35] respectively. CDV as defined in UNI 4.0 [5] and ITU Q.2965.2 [35] respectively.
The CDV parameters, <acdv> and <ccdv>, refer to the acceptable The CDV parameters, <acdv> and <ccdv>, refer to the acceptable
and cumulative CDVs respectively. These are expressed in units and cumulative CDVs respectively. These are expressed in units
of microseconds and represented as the decimal equivalent of microseconds and represented as the decimal equivalent
of a 24-bit field. These use the cell loss ratio, <aclr>, as the of a 24-bit field. These use the cell loss ratio, <aclr>, as the
"alpha" quantiles defined in the ATMF TM 4.1 specification [6] "alpha" quantiles defined in the ATMF TM 4.1 specification [6]
skipping to change at line 1667 skipping to change at line 1661
The transit delay parameters, <eetd> and <cmtd>, refer to the The transit delay parameters, <eetd> and <cmtd>, refer to the
end-to-end and cumulative transit delays respectively in end-to-end and cumulative transit delays respectively in
milliseconds. These are represented as the decimal equivalents milliseconds. These are represented as the decimal equivalents
of 16-bit fields. These parameters are defined in Q.2965.2 [35], of 16-bit fields. These parameters are defined in Q.2965.2 [35],
UNI 4.0 [5] and Q.2931 [15]. UNI 4.0 [5] and Q.2931 [15].
The <aclr> parameter refers to forward and backward acceptable The <aclr> parameter refers to forward and backward acceptable
cell loss ratios. This is the ratio between the number of cells cell loss ratios. This is the ratio between the number of cells
lost and the number of cells transmitted. It is expressed as the decimal lost and the number of cells transmitted. It is expressed as the decimal
Rajesh Kumar, Mohamed Mostafa. 32
equivalent of an 8-bit field. This field expresses an order of equivalent of an 8-bit field. This field expresses an order of
magnitude n, where n is an integer in the range 1-15. The Cell Loss magnitude n, where n is an integer in the range 1-15. The Cell Loss
Ratio takes on the value 10 raised to the power of minus n. Ratio takes on the value 10 raised to the power of minus n.
If any of these parameters is not specified, is inapplicable or is The <directionFlag> is always specified. Except for the <directionFlag>,
implied, then it is set to "-". the remaining parameters can be set to "-" to indicate that they are
not specified, inapplicable or implied. However, there must be some
specified parameters for the line to be useful in an SDP description.
There can be several 'atmQOSparms' lines in an SDP description.
An example use of these attributes for an rt-VBR, single-CID AAL2 An example use of these attributes for an rt-VBR, single-CID AAL2
voice VC is: voice VC is:
a=atmQOSfparms:pp 8125 3455 32000 - 11 a=atmQOSparms:f PP 8125 3455 32000 - 11
a=atmQOSbparms:pp 4675 2155 18000 - 12 a=atmQOSparms:b PP 4675 2155 18000 - 12
Rajesh Kumar, Mohamed Mostafa. 32
This implies a forward acceptable peak-to-peak CDV of 8.125 ms, a This implies a forward acceptable peak-to-peak CDV of 8.125 ms, a
backward acceptable peak-to-peak CDV of 4.675 ms, forward backward acceptable peak-to-peak CDV of 4.675 ms, forward
cumulative peak-to-peak CDV of 3.455 ms, a backward cumulative cumulative peak-to-peak CDV of 3.455 ms, a backward cumulative
peak-to-peak CDV of 2.155 ms, a forward end-to-end peak-to-peak CDV of 2.155 ms, a forward end-to-end
transit delay of 32 ms, a backward end-to-end transit delay of 32 ms, a backward end-to-end
transit delay of 18 ms, an unspecified forward cumulative transit delay of 18 ms, an unspecified forward cumulative
transit delay, an unspecified backward cumulative transit transit delay, an unspecified backward cumulative transit
delay, a forward cell loss ratio of 10 raised to minus 11 and a delay, a forward cell loss ratio of 10 raised to minus 11 and a
backward cell loss ratio of 10 to the minus 12. backward cell loss ratio of 10 to the minus 12.
5.6.1.9 The 'atmFtrfcDesc' and 'atmBtrfcDesc' attributes An example of specifying the same parameters for the forward
and backward directions is:
When present, the 'atmFtrfcDesc' and 'atmBtrfcDesc' attributes a=atmQOSparms:fb PP 8125 3455 32000 - 11
are used to indicate ATM traffic descriptor parameters in the
forward and backward directions respectively. See Section 2.3 for a
definition of the terms 'forward' and 'backward'.
The 'atmFtrfcDesc' and 'atmBtrfcDesc' media attribute lines This implies a forward and backward acceptable peak-to-peak CDV of
are structured as follows: 8.125 ms, a forward and backward cumulative peak-to-peak CDV of 3.455 ms,
a forward and backward end-to-end transit delay of 32 ms,
an unspecified cumulative transit delay in the forward and
backward directions, and a cell loss ratio of 10 raised to minus
11 in the forward and backward directions.
a=atmFtrfcDesc:<clpLvl> <pcr><scr><mbs><cdvt><mcr><mfs><fd><te> 5.6.1.9 The 'atmTrfcDesc' attribute
a=atmBtrfcDesc:<clpLvl> <pcr><scr><mbs><cdvt><mcr><mfs><fd><te>
If any of these parameters in these media attribute lines is not When present, the 'atmTrfcDesc' attribute is used to indicate
specified, is inapplicable or is implied, then it is set to "-". ATM traffic descriptor parameters. There can be several 'atmTrfcDesc'
lines in an SDP description.
The 'atmTrfcDesc' media attribute line is structured as follows:
a=atmTrfcDesc:<directionFlag><clpLvl>
<pcr><scr><mbs><cdvt><mcr><mfs><fd><te>
The <directionFlag> can be assigned the following string values: "f",
"b" and "fb". "f" and "b" indicate the forward and backward
Rajesh Kumar, Mohamed Mostafa. 33
directions respectively. "fb" refers to both directions (forward and
backward). Conventions for the forward and backward directions
are per section 2.3.
The <directionFlag> is always specified. Except for the <directionFlag>,
the remaining parameters can be set to "-" to indicate that they are
not specified, inapplicable or implied. However, there must be some
specified parameters for the line to be useful in an SDP description.
The <clpLvl> (CLP level) parameter indicates whether the rates and The <clpLvl> (CLP level) parameter indicates whether the rates and
bursts described in these media attribute lines apply to CLP bursts described in these media attribute lines apply to CLP
values of 0 or (0+1). It can take on the following string values: values of 0 or (0+1). It can take on the following string values:
"0", "0+1" and "-". If rates and bursts for both <clpLvl> values are to "0", "0+1" and "-". If rates and bursts for both <clpLvl> values are to
be described, then it is necessary to use two separate be described, then it is necessary to use two separate
media attribute lines for each direction in the same session media attribute lines for each direction in the same session
descriptor. If the <clpLvl> parameter is set to "-", then it descriptor. If the <clpLvl> parameter is set to "-", then it
implies that the CLP parameter is known by other means such as default, implies that the CLP parameter is known by other means such as default,
MIB provisioning etc. MIB provisioning etc.
The meaning, units and applicability of the remaining parameters The meaning, units and applicability of the remaining parameters
are per [6] and [28]: are per [6] and [28]:
Rajesh Kumar, Mohamed Mostafa. 33 Rajesh Kumar, Mohamed Mostafa. 34
PARAMETER MEANING UNITS APPLICABILITY PARAMETER MEANING UNITS APPLICABILITY
<pcr> PCR Cells/ CBR, rt-VBR, nrt-VBR, <pcr> PCR Cells/ CBR, rt-VBR, nrt-VBR,
second ABR, UBR, GFR; second ABR, UBR, GFR;
CLP=0,0+1 CLP=0,0+1
<scr> SCR Cells/ rt-VBR, nrt-VBR; <scr> SCR Cells/ rt-VBR, nrt-VBR;
second CLP=0,0+1 second CLP=0,0+1
<mbs> MBS Cells rt-VBR, nrt-VBR, <mbs> MBS Cells rt-VBR, nrt-VBR,
skipping to change at line 1768 skipping to change at line 1787
<te> (tag enable) indicates that CLP tagging is allowed. <te> (tag enable) indicates that CLP tagging is allowed.
These can take on the string values of "on" or "off". These can take on the string values of "on" or "off".
Since the <te> parameter applies only to cells with Since the <te> parameter applies only to cells with
a CLP of 0, it is meaningful in the case when <clpLvl> = "0". a CLP of 0, it is meaningful in the case when <clpLvl> = "0".
It should be set to "-" for the case when <clpLvl> = "0+1". It should be set to "-" for the case when <clpLvl> = "0+1".
An example use of these media attribute lines for an rt-VBR, An example use of these media attribute lines for an rt-VBR,
single-CID AAL2 voice VC is: single-CID AAL2 voice VC is:
Rajesh Kumar, Mohamed Mostafa. 34 Rajesh Kumar, Mohamed Mostafa. 35
a=atmFtrfcDesc:0+1 200 100 20 - - - on - a=atmTrfcDesc:f 0+1 200 100 20 - - - on -
a=atmFtrfcDesc:0 200 80 15 - - - - off a=atmTrfcDesc:f 0 200 80 15 - - - - off
a=atmBtrfcDesc:0+1 200 100 20 - - - on - a=atmTrfcDesc:b 0+1 200 100 20 - - - on -
a=atmBtrfcDesc:0 200 80 15 - - - - off a=atmTrfcDesc:b 0 200 80 15 - - - - off
This implies a forward and backward PCR of 200 cells per second This implies a forward and backward PCR of 200 cells per second
all cells regardless of CLP, forward and backward PCR of 200 cells all cells regardless of CLP, forward and backward PCR of 200 cells
per second for cells with CLP=0, a forward and backward SCR of 100 per second for cells with CLP=0, a forward and backward SCR of 100
cells per second for all cells regardless of CLP, a forward and cells per second for all cells regardless of CLP, a forward and
backward SCR of 80 cells per second for cells with CLP=0, backward SCR of 80 cells per second for cells with CLP=0,
a forward and backward MBS of 20 cells for all cells regardless a forward and backward MBS of 20 cells for all cells regardless
of CLP, a forward and backward MBS of 15 cells for cells with of CLP, a forward and backward MBS of 15 cells for cells with
CLP=0, an unspecified CDVT which can be known by other means, CLP=0, an unspecified CDVT which can be known by other means,
and an MCR and MFS which are unspecified because they are and an MCR and MFS which are unspecified because they are
inapplicable. Frame discard is enabled in both the forward and inapplicable. Frame discard is enabled in both the forward and
backward directions. Tagging is not enabled in either direction. backward directions. Tagging is not enabled in either direction.
The <pcr>, <scr>, <mbs>, <cdvt>, <mcr> and <mfs> are represented as The <pcr>, <scr>, <mbs>, <cdvt>, <mcr> and <mfs> are represented as
decimal integers, with range as defined in Section 6. See section 2.2 decimal integers, with range as defined in Section 6. See section 2.2
regarding the omission of leading zeros in decimal representations. regarding the omission of leading zeros in decimal representations.
5.6.1.10 The 'abrFparms' and 'abrBparms' attributes 5.6.1.10 The 'abrParms' attribute
When present, the 'abrFparms' and 'abrBparms' attributes When present, the 'abrParms' attribute is used to indicate the
are used to indicate the 'additional' ABR parameters specified 'additional' ABR parameters specified in the UNI
in the UNI 4.0 signaling specification [5]. These refer to the 4.0 signaling specification [5]. There can be several 'abrParms'
forward and backward directions respectively. See Section lines in an SDP description.
2.3 for a definition of the terms 'forward' and 'backward'.
The 'abrFparms' and 'abrBparms' media attribute lines are structured The 'abrParms' media attribute line is structured as follows:
as follows:
a=abrFparms:<nrm><trm><cdf><adtf> a=abrParms:<directionFlag><nrm><trm><cdf><adtf>
a=abrBparms:<nrm><trm><cdf><adtf>
The <directionFlag> can be assigned the following string values: "f",
"b" and "fb". "f" and "b" indicate the forward and backward
directions respectively. "fb" refers to both directions (forward and
backward). Conventions for the forward and backward directions
are per section 2.3.
The <directionFlag> is always specified. Except for the <directionFlag>,
the remaining parameters can be set to "-" to indicate that they are
not specified, inapplicable or implied. However, there must be some
specified parameters for the line to be useful in an SDP description.
These parameters are mapped into the ABR service parameters in These parameters are mapped into the ABR service parameters in
[6] in the manner described below. These parameters can be [6] in the manner described below. These parameters can be
represented in SDP as decimal integers, with fractions permitted represented in SDP as decimal integers, with fractions permitted
for some. Details of the meaning, units and applicability of for some. Details of the meaning, units and applicability of
these parameters are in [5] and [6]. these parameters are in [5] and [6].
If any of these parameters in the 'abrFparms' or 'abrBparms' media
attribute lines is not specified, is inapplicable or is implied,
then it is set to "-".
In SDP, these parameters are represented as the decimal or hex In SDP, these parameters are represented as the decimal or hex
equivalent of the binary fields mentioned below. equivalent of the binary fields mentioned below.
Rajesh Kumar, Mohamed Mostafa. 35 Rajesh Kumar, Mohamed Mostafa. 36
+-----------+----------------------------------+-----------------------+ +-----------+----------------------------------+-----------------------+
| PARAMETER | MEANING | FIELD SIZE | | PARAMETER | MEANING | FIELD SIZE |
+-----------+----------------------------------+-----------------------+ +-----------+----------------------------------+-----------------------+
| <nrm> | Maximum number of cells per | 3 bits | | <nrm> | Maximum number of cells per | 3 bits |
| | forward Resource Management cell | | | | forward Resource Management cell | |
+-----------+----------------------------------+-----------------------+ +-----------+----------------------------------+-----------------------+
| <trm> | Maximum time between | 3 bits | | <trm> | Maximum time between | 3 bits |
| | forward Resource Management cells| | | | forward Resource Management cells| |
+-----------+----------------------------------+-----------------------+ +-----------+----------------------------------+-----------------------+
| <cdf> | Cutoff Decrease Factor | 3 bits | | <cdf> | Cutoff Decrease Factor | 3 bits |
skipping to change at line 1844 skipping to change at line 1867
When present, the 'abrSetup' attribute is used to indicate the When present, the 'abrSetup' attribute is used to indicate the
ABR parameters needed during call/connection establishment (Section ABR parameters needed during call/connection establishment (Section
10.1.2.2 of the UNI 4.0 signaling specification [5]). This line 10.1.2.2 of the UNI 4.0 signaling specification [5]). This line
is structured as follows: is structured as follows:
a=abrSetup:<ficr><bicr><ftbe><btbe><crmrtt><frif><brif><frdf><brdf> a=abrSetup:<ficr><bicr><ftbe><btbe><crmrtt><frif><brif><frdf><brdf>
These parameters are defined as follows: These parameters are defined as follows:
Rajesh Kumar, Mohamed Mostafa. 36 Rajesh Kumar, Mohamed Mostafa. 37
+-----------+----------------------------------+-----------------------+ +-----------+----------------------------------+-----------------------+
| PARAMETER | MEANING | REPRESENTATION | | PARAMETER | MEANING | REPRESENTATION |
+-----------+----------------------------------+-----------------------+ +-----------+----------------------------------+-----------------------+
| <ficr> | Forward Initial Cell Rate | Decimal equivalent | | <ficr> | Forward Initial Cell Rate | Decimal equivalent |
| | (Cells per second) | of 24-bit field | | | (Cells per second) | of 24-bit field |
+-----------+----------------------------------+-----------------------+ +-----------+----------------------------------+-----------------------+
| <bicr> | Backward Initial Cell Rate | Decimal equivalent | | <bicr> | Backward Initial Cell Rate | Decimal equivalent |
| | (Cells per second) | of 24-bit field | | | (Cells per second) | of 24-bit field |
+-----------+----------------------------------+-----------------------+ +-----------+----------------------------------+-----------------------+
| <ftbe> | Forward transient buffer | Decimal equivalent | | <ftbe> | Forward transient buffer | Decimal equivalent |
skipping to change at line 1879 skipping to change at line 1902
| <frdf> | Forward rate decrease factor | Decimal integer | | <frdf> | Forward rate decrease factor | Decimal integer |
| | (used to derive cell count) | 0 -15 | | | (used to derive cell count) | 0 -15 |
+-----------+----------------------------------+-----------------------+ +-----------+----------------------------------+-----------------------+
| <brdf> | Backward rate decrease factor | Decimal integer | | <brdf> | Backward rate decrease factor | Decimal integer |
| | (used to derive cell count) | 0 -15 | | | (used to derive cell count) | 0 -15 |
+-----------+----------------------------------+-----------------------+ +-----------+----------------------------------+-----------------------+
See Section 2.3 for a definition of the terms 'forward' and 'backward'. See Section 2.3 for a definition of the terms 'forward' and 'backward'.
If any of these parameters in the 'abrSetup' media attribute line If any of these parameters in the 'abrSetup' media attribute line
is not specified, is inapplicable or is implied, then it is set to is not specified, is inapplicable or is implied, then it is set to h
"-". "-".
5.6.1.12 The 'bearerType' attribute 5.6.1.12 The 'bearerType' attribute
When present, the 'bearerType' attribute is used to indicate When present, the 'bearerType' attribute is used to indicate
whether the underlying bearer is an ATM PVC/SPVC, an ATM SVC, whether the underlying bearer is an ATM PVC/SPVC, an ATM SVC,
or an AAL2 CID connection within an existing ATM PVC/SPVC. or an AAL2 CID connection within an existing ATM PVC/SPVC.
Additionally, for ATM SVCs and AAL2 CID connections, the Additionally, for ATM SVCs and AAL2 CID connections, the
'bearerType' attribute can be used to indicate whether the 'bearerType' attribute can be used to indicate whether the
media gateway initiates connection set-up via bearer signaling media gateway initiates connection set-up via bearer signaling
(Q.2931-based or Q.2630.1 based). The format of the 'bearerType' (Q.2931-based or Q.2630.1 based). The format of the 'bearerType'
media attribute line is as follows: media attribute line is as follows:
a=bearerType: <bearerType> <localInitiation> a=bearerType: <bearerType> <localInitiation>
The <bearerType> field can take on the following string values: The <bearerType> field can take on the following string values:
Rajesh Kumar, Mohamed Mostafa. 37 Rajesh Kumar, Mohamed Mostafa. 38
"PVC", "SVC", "CID", with semantics as defined above. Here, "PVC" "PVC", "SVC", "CID", with semantics as defined above. Here, "PVC"
includes both the PVC and SPVC cases. includes both the PVC and SPVC cases.
In the case when the underlying bearer is a PVC/SPVC, or a CID In the case when the underlying bearer is a PVC/SPVC, or a CID
assigned by the MGC rather than through bearer signaling, the assigned by the MGC rather than through bearer signaling, the
<localInitiation> flag can be omitted or set to "-". In the <localInitiation> flag can be omitted or set to "-". In the
case when bearer signaling is used, this flag can be omitted case when bearer signaling is used, this flag can be omitted
when it is known by default or by other means whether the media when it is known by default or by other means whether the media
gateway initiates the connection set-up via bearer signaling. Only gateway initiates the connection set-up via bearer signaling. Only
when this is to be indicated explicitly that the <localInitiation> when this is to be indicated explicitly that the <localInitiation>
skipping to change at line 1950 skipping to change at line 1973
When present, the 'anycast' attribute line is used to indicate When present, the 'anycast' attribute line is used to indicate
the applicability of the anycast function described in UNI the applicability of the anycast function described in UNI
4.0 [5]. Optional parameters to qualify this function are 4.0 [5]. Optional parameters to qualify this function are
provided. The format of the 'anycast' attribute is: provided. The format of the 'anycast' attribute is:
a=anycast: <atmGroupAddress> <cdStd> <conScpTyp> <conScpSel> a=anycast: <atmGroupAddress> <cdStd> <conScpTyp> <conScpSel>
The <atmGroupAddress> is per Annex 5 of UNI 4.0 [5]. Within The <atmGroupAddress> is per Annex 5 of UNI 4.0 [5]. Within
an SDP descriptor, it can be represented in one of the formats an SDP descriptor, it can be represented in one of the formats
Rajesh Kumar, Mohamed Mostafa. 38 Rajesh Kumar, Mohamed Mostafa. 39
(NSAP, E.164, GWID/ALIAS) described elsewhere in this document. (NSAP, E.164, GWID/ALIAS) described elsewhere in this document.
The remaining subparameters mirror the connection scope selection The remaining subparameters mirror the connection scope selection
information element in UNI 4.0 [5]. Their meaning and representation information element in UNI 4.0 [5]. Their meaning and representation
is as shown below: is as shown below:
PARAMETER MEANING REPRESENTATION PARAMETER MEANING REPRESENTATION
<cdStd> Coding standard for the Decimal or hex <cdStd> Coding standard for the Decimal or hex
connection scope selection IE equivalent of connection scope selection IE equivalent of
Definition: UNI 4.0 [5] 2 bits Definition: UNI 4.0 [5] 2 bits
skipping to change at line 2000 skipping to change at line 2023
the network. This is specified as the decimal or hex equivalent of the network. This is specified as the decimal or hex equivalent of
a 32-bit field, indicating the timeout in seconds. As usual, leading a 32-bit field, indicating the timeout in seconds. As usual, leading
zeros can be omitted. For instance, zeros can be omitted. For instance,
a=cache:on 7200 a=cache:on 7200
implies that the cached SVC is to be deleted if it is idle for 2 hours. implies that the cached SVC is to be deleted if it is idle for 2 hours.
The <cacheTimer> can be set to "-" if it is inapplicable or implied. The <cacheTimer> can be set to "-" if it is inapplicable or implied.
Rajesh Kumar, Mohamed Mostafa. 40
5.6.1.16 The 'bearerSigIE' attribute 5.6.1.16 The 'bearerSigIE' attribute
ATM signaling standards provide 'escape mechanisms' to ATM signaling standards provide 'escape mechanisms' to
Rajesh Kumar, Mohamed Mostafa. 39
represent, signal and negotiate higher-layer parameters. Examples represent, signal and negotiate higher-layer parameters. Examples
are the B-HLI and B-LLI IEs specified in ITU Q.2931 [15], and are the B-HLI and B-LLI IEs specified in ITU Q.2931 [15], and
the user-to-user information element described in ITU Q.2957 [48]. the user-to-user information element described in ITU Q.2957 [48].
The 'bearerSigIE'(bearer signaling information element) attribute is The 'bearerSigIE'(bearer signaling information element) attribute is
defined to allow a similar escape mechanism that can be used with defined to allow a similar escape mechanism that can be used with
these ATM SDP conventions. The format of this media attribute line these ATM SDP conventions. The format of this media attribute line
is as follows: is as follows:
a=bearerSigIE: <bearerSigIEType> <bearerSigIELng> <bearerSigIEVal> a=bearerSigIE: <bearerSigIEType> <bearerSigIELng> <bearerSigIEVal>
skipping to change at line 2055 skipping to change at line 2077
controlling standard for an application layer above the ATM controlling standard for an application layer above the ATM
adaptation layer. adaptation layer.
* The 'cbrRate' attribute, which represents * The 'cbrRate' attribute, which represents
the CBR rate octet defined in Table 4-6 of ITU Q.2931 [15]. the CBR rate octet defined in Table 4-6 of ITU Q.2931 [15].
* The 'sbc' attribute, which denotes the * The 'sbc' attribute, which denotes the
subchannel count in the case of n x 64 clear channel subchannel count in the case of n x 64 clear channel
communication. communication.
Rajesh Kumar, Mohamed Mostafa. 41
* The 'clkrec' attribute, which indicates the clock recovery * The 'clkrec' attribute, which indicates the clock recovery
method for AAL1 unstructured data transfer (UDT). method for AAL1 unstructured data transfer (UDT).
Rajesh Kumar, Mohamed Mostafa. 40
* The 'fec' attribute, which indicates the use of * The 'fec' attribute, which indicates the use of
forward error correction. forward error correction.
* The 'prtfl' attribute, which indicates indicate the fill * The 'prtfl' attribute, which indicates indicate the fill
level of partially filled cells. level of partially filled cells.
* The 'structure' attribute, which is used to indicate * The 'structure' attribute, which is used to indicate
the presence or absence of AAL1 structured data transfer (SDT), the presence or absence of AAL1 structured data transfer (SDT),
and the size of the SDT blocks. and the size of the SDT blocks.
* The 'fcpsSDUsize' and 'bcpsSDUsize' * The 'cpsSDUsize' attribute, which is used to indicate the
attributes, which are used to indicate the maximum size of the maximum size of the CPCS SDU payload.
CPCS SDU payload in the forward and backward directions.
* The 'aal2CPS' attribute, which is used to * The 'aal2CPS' attribute, which is used to
indicate that an AAL2 CPS sublayer as defined in indicate that an AAL2 CPS sublayer as defined in
ITU I.363.2 [13] is associated with the VCC referred to in the ITU I.363.2 [13] is associated with the VCC referred to in the
'm' line. Optionally, it can be used to indicate selected 'm' line. Optionally, it can be used to indicate selected
CPS options and parameter values for this VCC. CPS options and parameter values for this VCC.
* The 'aal2CPSSDUrate' attribute, which is used to place * The 'aal2CPSSDUrate' attribute, which is used to place
an upper bound on the SDU bit rate for an AAL2 CID. an upper bound on the SDU bit rate for an AAL2 CID.
skipping to change at line 2110 skipping to change at line 2131
indicate the existence of an SSCOP protocol layer over indicate the existence of an SSCOP protocol layer over
an AAL5 CPS layer, and the parameters which pertain to an AAL5 CPS layer, and the parameters which pertain to
this SSCOP layer. this SSCOP layer.
5.6.2.1 The 'aalApp' attribute 5.6.2.1 The 'aalApp' attribute
When present, the 'aalApp' attribute is used to point to the When present, the 'aalApp' attribute is used to point to the
controlling standard for an application layer above the ATM adaptation controlling standard for an application layer above the ATM adaptation
layer. The format of the 'aalApp' media attribute line is as follows: layer. The format of the 'aalApp' media attribute line is as follows:
Rajesh Kumar, Mohamed Mostafa. 42
a=aalApp: <appClass> <oui> <appId> a=aalApp: <appClass> <oui> <appId>
Rajesh Kumar, Mohamed Mostafa. 41
If any of the subparameters, <appClass>, <oui> or <appId>, is meant If any of the subparameters, <appClass>, <oui> or <appId>, is meant
to be left, unspecified, it is set to "-". However, an 'aalApp' attribute to be left, unspecified, it is set to "-". However, an 'aalApp' attribute
line with all subparameters set to "-" carries no information and line with all subparameters set to "-" carries no information and
should be omitted. should be omitted.
The <appClass>, or application class, field can take on the The <appClass>, or application class, field can take on the
string values listed below. string values listed below.
This list is not exhaustive. An "X-" prefix should be used with This list is not exhaustive. An "X-" prefix should be used with
<appClass> values not listed here. <appClass> values not listed here.
skipping to change at line 2163 skipping to change at line 2184
This uses SSCOP [43]. This uses SSCOP [43].
"itu_i3653" Service-specific coordination function, "itu_i3653" Service-specific coordination function,
as defined in ITU I.365.3, for Connection as defined in ITU I.365.3, for Connection
Oriented Transport Service (SSCF-COTS) [41]. Oriented Transport Service (SSCF-COTS) [41].
This uses SSCOP [43]. This uses SSCOP [43].
"itu_i3654" HDLC Service-specific coordination function, "itu_i3654" HDLC Service-specific coordination function,
as defined in ITU I.365.4 [42]. as defined in ITU I.365.4 [42].
Rajesh Kumar, Mohamed Mostafa. 43
"FRF5" Use of the FRF.5 frame relay standard [53], "FRF5" Use of the FRF.5 frame relay standard [53],
Rajesh Kumar, Mohamed Mostafa. 42
which references ITU I.365.1 [39]. which references ITU I.365.1 [39].
"FRF8" Use of the FRF.8.1 frame relay standard [54]. "FRF8" Use of the FRF.8.1 frame relay standard [54].
This implies a null SSCS and the mapping of This implies a null SSCS and the mapping of
the frame relay header into the ATM header. the frame relay header into the ATM header.
"FRF11" Use of the FRF.11 frame relay standard [55]. "FRF11" Use of the FRF.11 frame relay standard [55].
"itu_h2221" Use of the ITU standard H.222.1 for audiovisual "itu_h2221" Use of the ITU standard H.222.1 for audiovisual
communication over AAL5 [51]. communication over AAL5 [51].
The <oui>, or Organizationally Unique Identifier, refers to the organization The <oui>, or Organizationally Unique Identifier, refers to the organization
responsible for defining the <appId>, or Application Identifier. The <oui> is responsible for defining the <appId>, or Application Identifier. The <oui> is
maintained by the IEEE. One of its uses is in 802 MAC addresses. It is a three- maintained by the IEEE. One of its uses is in 802 MAC addresses. It is a three-
octet field represented as one to six hex digits. Since this is always octet field represented as one to six hex digits. Since this is always
represented in hex, the "0x" prefix is not used. Leading zeros may be omitted. represented in hex, the "0x" prefix is not used. Leading zeros may be omitted.
The <appId> subparameter refers to the application ID, a hex number consisting The <appId> subparameter refers to the application ID, a hex number consisting
of up to 8 digits. Leading zeros may be omitted. The "0x" prefix is not used, of up to 8 digits. Leading zeros may be omitted. The "0x" prefix is not used,
since the representation is always hexadecimal. Currently, the only since the representation is always hexadecimal. Currently, the only
organization that has defined applicable application identifiers is the ATM organization that has defined application identifiers is the ATM forum. These
forum (Section 5 of [61]). These can be used with <appClass> = itu_i3662. The have been defined in the context of AAL2 ([44], [52], Section 5 of [61]).
<oui> value for the ATM forum is 0x00A03E. Within SDP, these can be used with <appClass> = itu_i3662. The <oui> value for
the ATM forum is 0x00A03E.
In the following example, the aalApp media attribute line is used to In the following example, the aalApp media attribute line is used to
indicate 'Loop Emulation Service using CAS (POTS only) without the indicate 'Loop Emulation Service using CAS (POTS only) without the
Emulated Loop Control Protocol (ELCP) [52]. The Application ID is defined Emulated Loop Control Protocol (ELCP) [52]. The Application ID is defined
by the ATM forum [61]. The SSCS used is per ITU I.366.2 [13]. by the ATM forum [61]. The SSCS used is per ITU I.366.2 [13].
a=aalApp:itu_i3662 A03E A a=aalApp:itu_i3662 A03E A
If leading zeros are not dropped, this can be represented as: If leading zeros are not dropped, this can be represented as:
a=aalApp:itu_i3662 00A03E 0000000A a=aalApp:itu_i3662 00A03E 0000000A
Since application identifiers have been specified only in the context of the
AAL2 SSCS defined in ITU I.366.2 [13],the <appClass> can be set to '-' without
ambiguity. The aalApp media attribute line can be reduced to:
a=aalApp:- A03E A
or
a=aalApp:- 00A03E 0000000A
5.6.2.2 The 'cbrRate' attribute 5.6.2.2 The 'cbrRate' attribute
When present, the 'cbrRate' attribute is used to represent the CBR When present, the 'cbrRate' attribute is used to represent the CBR
Rajesh Kumar, Mohamed Mostafa. 44
rate octet defined in Table 4-6 of ITU Q.2931 [15]. The format rate octet defined in Table 4-6 of ITU Q.2931 [15]. The format
of this media attribute line is: of this media attribute line is:
a=cbrRate: <cbrRate> a=cbrRate: <cbrRate>
Here, <cbrRate> is represented as exactly two hex digits. The "0x" Here, <cbrRate> is represented as exactly two hex digits. The "0x"
prefix is omitted since this parameter is always represented in prefix is omitted since this parameter is always represented in
hex. Values currently defined by the ITU are: hex. Values currently defined by the ITU are:
Rajesh Kumar, Mohamed Mostafa. 43
+------------+-----------------------------------------------+ +------------+-----------------------------------------------+
| VALUE | MEANING | | VALUE | MEANING |
| (hex) | |
+------------+-----------------------------------------------+ +------------+-----------------------------------------------+
| 0x01 | 64 kbps | | 01 | 64 kbps |
+------------+-----------------------------------------------+ +------------+-----------------------------------------------+
| 0x04 | 1544 kbps | | 04 | 1544 kbps |
+------------+-----------------------------------------------+ +------------+-----------------------------------------------+
| 0x05 | 6312 kbps | | 05 | 6312 kbps |
+------------+-----------------------------------------------+ +------------+-----------------------------------------------+
| 0x06 | 32064 kbps | | 06 | 32064 kbps |
+------------+-----------------------------------------------+ +------------+-----------------------------------------------+
| 0x07 | 44736 kbps | | 07 | 44736 kbps |
+------------+-----------------------------------------------+ +------------+-----------------------------------------------+
| 0x08 | 97728 kbps | | 08 | 97728 kbps |
+------------+-----------------------------------------------+ +------------+-----------------------------------------------+
| 0x10 | 2048 kbps | | 10 | 2048 kbps |
+------------+-----------------------------------------------+ +------------+-----------------------------------------------+
| 0x11 | 8448 kbps | | 11 | 8448 kbps |
+------------+-----------------------------------------------+ +------------+-----------------------------------------------+
| 0x12 | 34368 kbps | | 12 | 34368 kbps |
+------------+-----------------------------------------------+ +------------+-----------------------------------------------+
| 0x13 | 139264 kbps | | 13 | 139264 kbps |
+------------+-----------------------------------------------+ +------------+-----------------------------------------------+
| 0x40 | n x 64 kbps | | 40 | n x 64 kbps |
+------------+-----------------------------------------------+ +------------+-----------------------------------------------+
| 0x41 | n x 8 kbps | | 41 | n x 8 kbps |
+------------+-----------------------------------------------+ +------------+-----------------------------------------------+
It is preferable that the cbrRate attribute be omitted rather It is preferable that the cbrRate attribute be omitted rather
than set to an unspecified value of "-", since it conveys no than set to an unspecified value of "-", since it conveys no
information in the latter case. information in the latter case.
5.6.2.3 The 'sbc' attribute 5.6.2.3 The 'sbc' attribute
The 'sbc' media attribute line denotes the subchannel count and The 'sbc' media attribute line denotes the subchannel count and
is meaningful only in the case of n x 64 clear channel communication. is meaningful only in the case of n x 64 clear channel communication.
A clear n x 64 channel can use AAL1 (ATM forum af-vtoa-78) or AAL2 A clear n x 64 channel can use AAL1 (ATM forum af-vtoa-78) or AAL2
adaptation (ITU I.366.2). Although no such standard definition exists, adaptation (ITU I.366.2). Although no such standard definition exists,
it is also possible to use AAL5 for this purpose. An n x 64 clear channel it is also possible to use AAL5 for this purpose. An n x 64 clear channel
is represented by the encoding names of "X-CCD" and "X-CCD-CAS" in is represented by the encoding names of "X-CCD" and "X-CCD-CAS" in
Table 2. Table 2.
Rajesh Kumar, Mohamed Mostafa. 45
The format of the 'sbc' media attribute line is as follows: The format of the 'sbc' media attribute line is as follows:
a=sbc:<sbc> a=sbc:<sbc>
Here, <sbc> can be expressed as a decimal or hex integer. This Here, <sbc> can be expressed as a decimal or hex integer. This
attribute indicates the number of DS0s in a T1 or E1 frame that are attribute indicates the number of DS0s in a T1 or E1 frame that are
aggregated for transmitting clear channel data. For T1-based aggregated for transmitting clear channel data. For T1-based
applications, it can take on integral values in the inclusive range applications, it can take on integral values in the inclusive range
[1...24]. For E1-based applications, it can take on integral values in [1...24]. For E1-based applications, it can take on integral values in
the inclusive range [1...31]. When omitted, other means are to be used the inclusive range [1...31]. When omitted, other means are to be used
Rajesh Kumar, Mohamed Mostafa. 44
to determine the subchannel count. to determine the subchannel count.
Use of the 'sbc' attribute provides a direct way to indicate the Use of the 'sbc' attribute provides a direct way to indicate the
number of 64 kbps subchannels bundled into an n x 64 clear number of 64 kbps subchannels bundled into an n x 64 clear
channel. An alternate mechanism to indicate this exists within channel. An alternate mechanism to indicate this exists within
the SDP bandwidth information, or 'b', line [1]. In this case, the SDP bandwidth information, or 'b', line [1]. In this case,
instead of specifying the number of subchannels, the aggregate instead of specifying the number of subchannels, the aggregate
bandwidth in kbps is specified. The syntax of the 'b' line, copied bandwidth in kbps is specified. The syntax of the 'b' line, copied
verbatim from [1], is as follows: verbatim from [1], is as follows:
skipping to change at line 2306 skipping to change at line 2338
b=AS:384 b=AS:384
The media attribute line The media attribute line
a=sbc:2 a=sbc:2
is equivalent to is equivalent to
b=AS:128 b=AS:128
Rajesh Kumar, Mohamed Mostafa. 46
5.6.2.4 The 'clkrec' attribute 5.6.2.4 The 'clkrec' attribute
When present, the 'clkrec' attribute is used to indicate When present, the 'clkrec' attribute is used to indicate
the clock recovery method. This attribute is meaningful in the the clock recovery method. This attribute is meaningful in the
case of AAL1 unstructured data transfer (UDT). The format of the case of AAL1 unstructured data transfer (UDT). The format of the
'clkrec' media attribute line is as follows: 'clkrec' media attribute line is as follows:
a=clkrec:<clkrec> a=clkrec:<clkrec>
The <clkrec> field can take on the following string values: "NULL", The <clkrec> field can take on the following string values: "NULL",
"SRTS" or "ADAPTIVE". SRTS and adaptive clock recovery are defined in "SRTS" or "ADAPTIVE". SRTS and adaptive clock recovery are defined in
ITU I.363.1 [10]. "NULL" indicates that the stream (e.g. T1/E1) ITU I.363.1 [10]. "NULL" indicates that the stream (e.g. T1/E1)
encapsulated in ATM is synchronous to the ATM network or is retimed, encapsulated in ATM is synchronous to the ATM network or is retimed,
before AAL1 encapsulation, via slip buffers. before AAL1 encapsulation, via slip buffers.
Rajesh Kumar, Mohamed Mostafa. 45
5.6.2.5 The 'fec' attribute 5.6.2.5 The 'fec' attribute
When present, the 'fec' attribute is used to indicate the use of When present, the 'fec' attribute is used to indicate the use of
forward error correction. Currently, there exists a forward error forward error correction. Currently, there exists a forward error
correction method defined for AAL1 in ITU I.363.1 [10]. The format of the correction method defined for AAL1 in ITU I.363.1 [10]. The format of the
'fec' media attribute line is as follows: 'fec' media attribute line is as follows:
a=fec:<fecEnable> a=fec:<fecEnable>
The <fecEnable> flag indicates the presence of absence of Forward The <fecEnable> flag indicates the presence of absence of Forward
skipping to change at line 2360 skipping to change at line 2392
The format of the 'prtfl' media attribute line is as follows: The format of the 'prtfl' media attribute line is as follows:
a=prtfl:<partialFill> a=prtfl:<partialFill>
Here, <partialFill> can be expressed as a decimal or a hex integer. Here, <partialFill> can be expressed as a decimal or a hex integer.
In general, permitted values are integers in the range 1 - 48 In general, permitted values are integers in the range 1 - 48
inclusive. However, this upper bound is different for different inclusive. However, this upper bound is different for different
adaptations since the AAL overhead, if any, is different. If the specified adaptations since the AAL overhead, if any, is different. If the specified
partial fill is greater than or equal to the maximum fill, then complete partial fill is greater than or equal to the maximum fill, then complete
Rajesh Kumar, Mohamed Mostafa. 47
fill is used. Using a 'partial' fill of 48 always disables partial fill. fill is used. Using a 'partial' fill of 48 always disables partial fill.
In the AAL1 context, this media attribute line applies uniformly to In the AAL1 context, this media attribute line applies uniformly to
both P and non-P cells. In AAL1 applications that do not distinguish both P and non-P cells. In AAL1 applications that do not distinguish
between P and non-P cells, a value of 47 indicates complete fill (i.e. the between P and non-P cells, a value of 47 indicates complete fill (i.e. the
absence of partial fill). In AAL1 applications that distinguish between P absence of partial fill). In AAL1 applications that distinguish between P
and non-P cells, a value of 46 indicates no padding in P-cells and a and non-P cells, a value of 46 indicates no padding in P-cells and a
padding of one in non-P cells. padding of one in non-P cells.
If partial fill is enabled (i.e there is padding in at least some If partial fill is enabled (i.e there is padding in at least some
cells), then AAL1 structures must not be split across cell boundaries. cells), then AAL1 structures must not be split across cell boundaries.
These shall fit in any cell. Hence, These shall fit in any cell. Hence,
their size shall be less than or equal to the partial fill their size shall be less than or equal to the partial fill
size. Further, the partial fill size is preferably size. Further, the partial fill size is preferably
Rajesh Kumar, Mohamed Mostafa. 46
an integer multiple of the structure size. If not, then the an integer multiple of the structure size. If not, then the
partial fill size stated in the SDP description shall be partial fill size stated in the SDP description shall be
truncated to an integer multiple (e.g. a partial fill size of truncated to an integer multiple (e.g. a partial fill size of
40 is truncated to 36 to support six 6 x 64 channels). 40 is truncated to 36 to support six 6 x 64 channels).
5.6.2.7 The 'structure' attribute 5.6.2.7 The 'structure' attribute
This attribute applies to AAL1 connections only. When present, This attribute applies to AAL1 connections only. When present,
the 'structure' attribute is used to indicate the presence or the 'structure' attribute is used to indicate the presence or
absence of structured data transfer (SDT), and the size in octets absence of structured data transfer (SDT), and the size in octets
of the SDT blocks. The format of the 'structure' media attribute line of the SDT blocks. The format of the 'structure' media attribute line
is as follows: is as follows:
a=structure: <structureEnable> <blksz> a=structure: <structureEnable> <blksz>
where the <structureEnable> flag indicates the presence of absence of SDT. where the <structureEnable> flag indicates the presence of absence of SDT.
It can take on the values of "on" or "off". An "on" value implies It can take on the values of "on" or "off". An "on" value implies
AAL1 structured data transfer (SDT), while an "off" value implies AAL1 structured data transfer (SDT), while an "off" value implies
AAL1 unstructured data transfer (UDT). AAL1 unstructured data transfer (UDT).
The block size field, <blksz>, is an optional 16-bit field (Q.2931) The block size field, <blksz>, is an optional 16-bit field [15]
that can be represented in decimal or hex. It is set to that can be represented in decimal or hex. It is set to
a "-" when not applicable, as in the case of unstructured data transfer a "-" when not applicable, as in the case of unstructured data transfer
(UDT). For SDT, it can be set to a "-" when <blksz> is known (UDT). For SDT, it can be set to a "-" when <blksz> is known
by other means. For instance, af-vtoa-78 [7] fixes the structure size for by other means. For instance, af-vtoa-78 [7] fixes the structure size for
n x 64 service, with or without CAS. The theoretical maximum value of n x 64 service, with or without CAS. The theoretical maximum value of
<blksz> is 65,535, although most services use much less. <blksz> is 65,535, although most services use much less.
5.6.2.8 The 'fcpsSDUsize' and 'bcpsSDUsize' attributes 5.6.2.8 The 'cpsSDUsize' attribute
When present, the 'fcpsSDUsize' and 'bcpsSDUsize' attributes are used to When present, the 'cpsSDUsize' attribute is used to
indicate the maximum size of the CPCS SDU payload in the forward and indicate the maximum size of the CPCS SDU payload. There can be
backward directions respectively. See section 2.3 for a definition of the several 'cpsSDUsize' lines in an SDP description.
terms 'forward' and 'backward'. The format of these media attribute lines is
as follows:
a=fcpsSDUsize: <cpcs> The format of this media attribute line is as follows:
a=bcpsSDUsize: <cpcs>
a=cpsSDUsize:<directionFlag><cpcs>
Rajesh Kumar, Mohamed Mostafa. 48
The <directionFlag> can be assigned the following string values: "f",
"b" and "fb". "f" and "b" indicate the forward and backward
directions respectively. "fb" refers to both directions (forward and
backward). Conventions for the forward and backward directions
are per section 2.3.
The <cpcs> fields is a 16-bit integer that can be represented in The <cpcs> fields is a 16-bit integer that can be represented in
decimal or in hex. decimal or in hex. The meaning and values of these fields are as
The meaning and values of these fields are as follows: follows:
Application Field Meaning Values Application Field Meaning Values
AAL5 <cpcs> Maximum CPCS-SDU size 1- 65,535 AAL5 <cpcs> Maximum CPCS-SDU size 1- 65,535
AAL2 <cpcs> Maximum CPCS-SDU size 45 or 64 AAL2 <cpcs> Maximum CPCS-SDU size 45 or 64
Rajesh Kumar, Mohamed Mostafa. 47
5.6.2.9 The 'aal2CPS' attribute 5.6.2.9 The 'aal2CPS' attribute
When present, the 'aal2CPS' attribute is used to describe When present, the 'aal2CPS' attribute is used to describe
parameters associated with the AAL2 CPS layer. parameters associated with the AAL2 CPS layer.
The format of the 'aal2CPS' media attribute line is as follows: The format of the 'aal2CPS' media attribute line is as follows:
a=aal2CPS:<cidLowerLimit><cidUpperLimit><timerCU> <simplifiedCPS> a=aal2CPS:<cidLowerLimit><cidUpperLimit><timerCU> <simplifiedCPS>
Each of these fields can be set to a "-" when the intention is to not Each of these fields can be set to a "-" when the intention is to not
specify them in an SDP descriptor. specify them in an SDP descriptor.
The <cidLowerLimit> and <cidUpperLimit> can be assigned integer The <cidLowerLimit> and <cidUpperLimit> can be assigned integer
values between 8 and 255 [11], with the limitation that <cidUpperLimit> values between 8 and 255 [11], with the limitation that <cidUpperLimit>
be greater than or equal to <cidLowerLimit>. For instance, for POTS be greater than or equal to <cidLowerLimit>. For instance, for POTS
applications based on [52], <cidLowerLimit> and <cidUpperLimit> applications based on [52], <cidLowerLimit> and <cidUpperLimit>
can have values of 16 and 223 respectively. can have values of 16 and 223 respectively.
The <timerCU> integer represents the "combined use" timerCU defined in The <timerCU> integer represents the "combined use" timerCU defined in
ITU I.363.2. This timer is represented as an integer number of microseconds. ITU I.363.2. This timer is represented as an integer number of microseconds.
It is represented as the decimal integer equivalent of 32 bits.
The <simplifiedCPS> parameter can be assigned the values "on" or "off". When The <simplifiedCPS> parameter can be assigned the values "on" or "off". When
it is "on", the AAL2 CPS simplification described in [52] is adopted. Under it is "on", the AAL2 CPS simplification described in [52] is adopted. Under
this simplification, each ATM cell contains exactly on AAL2 packet. If this simplification, each ATM cell contains exactly on AAL2 packet. If
necessary, octets at the end of the cell are padded with zeros. Since the necessary, octets at the end of the cell are padded with zeros. Since the
<timerCU> value in this context is always 0, it can be omitted. <timerCU> value in this context is always 0, it can be set to "-".
5.6.2.10 The 'aal2CPSSDUrate' attribute 5.6.2.10 The 'aal2CPSSDUrate' attribute
When present, the 'aal2CPSSDUrate' attribute is used to place an upper When present, the 'aal2CPSSDUrate' attribute is used to place an upper
bound on the SDU bit rate for an AAL2 CID. This is useful for bound on the SDU bit rate for an AAL2 CID. This is useful for
limiting the bandwidth used by a CID, specially if the CID is used limiting the bandwidth used by a CID, specially if the CID is used
for frame mode data defined in [13], or with the SSSAR defined in for frame mode data defined in [13], or with the SSSAR defined in
Rajesh Kumar, Mohamed Mostafa. 49
[12]. The format of this media attribute line is as follows: [12]. The format of this media attribute line is as follows:
a=aal2CPSSDUrate: <fSDUrate><bSDUrate> a=aal2CPSSDUrate: <fSDUrate><bSDUrate>
The fSDUrate and bSDUrate are the maximum forward and backward SDU The fSDUrate and bSDUrate are the maximum forward and backward SDU
rates in bits/second. These are represented as rates in bits/second. These are represented as
decimal integers, with range as defined in Section 6. If any decimal integers, with range as defined in Section 6. If any
of these parameters in these media attribute lines is not of these parameters in these media attribute lines is not
specified, is inapplicable or is implied, then it is set to "-". specified, is inapplicable or is implied, then it is set to "-".
skipping to change at line 2480 skipping to change at line 2519
When present, the 'aal2sscs3661unassured' attribute is used to indicate When present, the 'aal2sscs3661unassured' attribute is used to indicate
the options that pertain to the unassured transmission SSCS defined the options that pertain to the unassured transmission SSCS defined
in ITU I.366.1 [12]. This SSCS can be selected via the aalApp in ITU I.366.1 [12]. This SSCS can be selected via the aalApp
attribute defined below, or by virtue of the presence of the attribute defined below, or by virtue of the presence of the
'aal2sscs3661unassured' attribute. The format of this 'aal2sscs3661unassured' attribute. The format of this
media attribute line is as follows: media attribute line is as follows:
a=aal2sscs3661unassured: <ted> <rastimer> <fsssar> <bsssar> a=aal2sscs3661unassured: <ted> <rastimer> <fsssar> <bsssar>
Rajesh Kumar, Mohamed Mostafa. 48
Each of these fields can be set to a "-" when the intention is to not Each of these fields can be set to a "-" when the intention is to not
specify them in an SDP descriptor. specify them in an SDP descriptor.
The <ted> flag indicates the presence or absence of transmission The <ted> flag indicates the presence or absence of transmission
error detection as defined in I.366.1. It can be assigned the error detection as defined in I.366.1. It can be assigned the
values of "on" or "off". An "on" value indicates presence of values of "on" or "off". An "on" value indicates presence of
the capability. the capability.
The <rastimer> subparameter indicates the SSSAR reassembly timer The <rastimer> subparameter indicates the SSSAR reassembly timer
in microseconds. It is represented as the decimal equivalent of in microseconds. It is represented as the decimal equivalent of
skipping to change at line 2511 skipping to change at line 2549
<bsssar> Maximum SSSAR-SDU size 1- 65,568 <bsssar> Maximum SSSAR-SDU size 1- 65,568
backward direction backward direction
If present, the SSTED (Service-Specific Transmission Error If present, the SSTED (Service-Specific Transmission Error
Detection) sublayer is above the SSSAR (Service-Specific Segmentation Detection) sublayer is above the SSSAR (Service-Specific Segmentation
and Reassembly) sublayer [12]. Since the maximum size of the and Reassembly) sublayer [12]. Since the maximum size of the
SSTED-SDUs can be derived from the maximum SSSAR-SDU size, it need SSTED-SDUs can be derived from the maximum SSSAR-SDU size, it need
not be specified separately. not be specified separately.
Rajesh Kumar, Mohamed Mostafa. 50
5.6.2.12 The 'aal2sscs3661assured' attribute 5.6.2.12 The 'aal2sscs3661assured' attribute
When present, the 'aal2sscs3661assured' attribute is used to indicate When present, the 'aal2sscs3661assured' attribute is used to indicate
the options that pertain to the assured transmission SSCS defined the options that pertain to the assured transmission SSCS defined
in ITU I.366.1 [12] on the basis of ITU Q.2110 [43]. This SSCS can be in ITU I.366.1 [12] on the basis of ITU Q.2110 [43]. This SSCS can be
selected via the aalApp attribute defined below, or by virtue selected via the aalApp attribute defined below, or by virtue
of the presence of the 'aal2sscs3661assured' attribute. The format of of the presence of the 'aal2sscs3661assured' attribute. The format of
this media attribute line is as follows: this media attribute line is as follows:
a=aal2sscs3661assured: <rastimer> <fsssar> <bsssar> <fsscopsdu> a=aal2sscs3661assured: <rastimer> <fsssar> <bsssar> <fsscopsdu>
<bsscopsdu><fsscopuu> <bsscopuu> <bsscopsdu><fsscopuu> <bsscopuu>
Each of these fields can be set to a "-" when the intention is to not Each of these fields can be set to a "-" when the intention is to not
specify them in an SDP descriptor. specify them in an SDP descriptor.
The <rastimer> subparameter indicates the SSSAR reassembly timer The <rastimer> subparameter indicates the SSSAR reassembly timer
in microseconds. It is represented as the decimal equivalent of in microseconds. It is represented as the decimal equivalent of
32 bits. 32 bits.
The <fsssar> and <bsssar> fields are 24-bit integers that The <fsssar> and <bsssar> fields are 24-bit integers that
Rajesh Kumar, Mohamed Mostafa. 49
can be represented in decimal or in hex. The <fsscopsdu>, can be represented in decimal or in hex. The <fsscopsdu>,
<bsscopsdu>, <fsscopuu> and <bsscopuu> fields are 16-bit integers <bsscopsdu>, <fsscopuu> and <bsscopuu> fields are 16-bit integers
that can be represented in decimal or in hex. The meaning and values that can be represented in decimal or in hex. The meaning and values
of these fields is as follows: of these fields is as follows:
Field Meaning Values Field Meaning Values
<fsssar> Maximum SSSAR-SDU size 1- 65,568 <fsssar> Maximum SSSAR-SDU size 1- 65,568
forward direction forward direction
skipping to change at line 2565 skipping to change at line 2603
<bsscopuu> Maximum SSCOP-UU field 1- 65,524 <bsscopuu> Maximum SSCOP-UU field 1- 65,524
size, backward direction size, backward direction
The SSTED (Service-Specific Transmission Error Detection) sublayer The SSTED (Service-Specific Transmission Error Detection) sublayer
is above the SSSAR (Service-Specific Segmentation and Reassembly) is above the SSSAR (Service-Specific Segmentation and Reassembly)
sublayer [12]. The SSADT (Service-Specific Assured Data Transfer) sublayer [12]. The SSADT (Service-Specific Assured Data Transfer)
sublayer is above the SSTED sublayer. Since the maximum size of sublayer is above the SSTED sublayer. Since the maximum size of
the SSTED-SDUs and SSADT-SDUs can be derived from the maximum the SSTED-SDUs and SSADT-SDUs can be derived from the maximum
SSSAR-SDU size, they need not be specified separately. SSSAR-SDU size, they need not be specified separately.
Rajesh Kumar, Mohamed Mostafa. 51
The SSCOP protocol defined in [43] is used by the Assured Data The SSCOP protocol defined in [43] is used by the Assured Data
Transfer service defined in [12]. In the context of the ITU I.366.1 Transfer service defined in [12]. In the context of the ITU I.366.1
SSCS, it is possible to use the 'aal2sscs3661assured' attribute to limit SSCS, it is possible to use the 'aal2sscs3661assured' attribute to limit
the maximum sizes of the SSCOP SDUs and UU (user-to-user) fields in the maximum sizes of the SSCOP SDUs and UU (user-to-user) fields in
either direction. Note that it is necessary for the parameters on the either direction. Note that it is necessary for the parameters on the
'aal2sscs3661assured' media attribute line to be consistent with each 'aal2sscs3661assured' media attribute line to be consistent with each
other. other.
5.6.2.13 The 'aal2sscs3662' attribute 5.6.2.13 The 'aal2sscs3662' attribute
When present, the 'aal2sscs3662' attribute is used to indicate When present, the 'aal2sscs3662' attribute is used to indicate
the options that pertain to the SSCS defined in ITU I.366.2 [13]. the options that pertain to the SSCS defined in ITU I.366.2 [13].
This SSCS can be selected via the aalApp attribute defined below, This SSCS can be selected via the aalApp attribute defined below,
or by the presence of the 'aal2sscs3662' attribute. or by the presence of the 'aal2sscs3662' attribute.
The format of this media attribute line is as follows: The format of this media attribute line is as follows:
Rajesh Kumar, Mohamed Mostafa. 50
a=aal2sscs3662: <sap> <circuitMode> <frameMode> <faxDemod> a=aal2sscs3662: <sap> <circuitMode> <frameMode> <faxDemod>
<cas> <dtmf> <mfall> <mfr1> <mfr2> <cas> <dtmf> <mfall> <mfr1> <mfr2>
<PCMencoding> <fmaxFrame> <bmaxFrame> <PCMencoding> <fmaxFrame> <bmaxFrame>
Each of these fields can be set to a "-" when the intention Each of these fields can be set to a "-" when the intention
is to not specify them in an SDP descriptor. Additionally, the values is to not specify them in an SDP descriptor. Additionally, the values
of these fields need to be consistent with each other. Inconsistencies of these fields need to be consistent with each other. Inconsistencies
should be flagged as errors. should be flagged as errors.
The <sap> field can take on the following string values: "AUDIO" The <sap> field can take on the following string values: "AUDIO"
skipping to change at line 2618 skipping to change at line 2655
The <frameMode> flag indicates whether the transport of frame The <frameMode> flag indicates whether the transport of frame
mode data is enabled or disabled, corresponding to the string mode data is enabled or disabled, corresponding to the string
values of "on" and "off" respectively. values of "on" and "off" respectively.
The <faxDemod> flag indicates whether facsimile demodulation The <faxDemod> flag indicates whether facsimile demodulation
and remodulation are enabled or disabled, corresponding to the and remodulation are enabled or disabled, corresponding to the
string values of "on" and "off" respectively. string values of "on" and "off" respectively.
The <cas> flag indicates whether the transport of Channel The <cas> flag indicates whether the transport of Channel
Rajesh Kumar, Mohamed Mostafa. 52
Associated Signaling (CAS) bits in AAL2 type 3 packets is enabled Associated Signaling (CAS) bits in AAL2 type 3 packets is enabled
or disabled, corresponding to the string values of "on" and "off" or disabled, corresponding to the string values of "on" and "off"
respectively. respectively.
The <dtmf> flag indicates whether the transport of DTMF dialled The <dtmf> flag indicates whether the transport of DTMF dialled
digits in AAL2 type 3 packets is enabled or disabled, corresponding digits in AAL2 type 3 packets is enabled or disabled, corresponding
to the string values of "on" and "off" respectively. to the string values of "on" and "off" respectively.
The <mfall> flag indicates whether the transport of MF dialled The <mfall> flag indicates whether the transport of MF dialled
digits in AAL2 type 3 packets is enabled or disabled, corresponding digits in AAL2 type 3 packets is enabled or disabled, corresponding
to the string values of "on" and "off" respectively. This flag to the string values of "on" and "off" respectively. This flag
enables MF dialled digits in a generic manner, without specifying enables MF dialled digits in a generic manner, without specifying
type (e.g. R1, R2 etc.). type (e.g. R1, R2 etc.).
The <mfr1> flag indicates whether the transport, in AAL2 type 3 The <mfr1> flag indicates whether the transport, in AAL2 type 3
packets, of MF dialled digits for signaling system R1 is enabled packets, of MF dialled digits for signaling system R1 is enabled
or disabled, corresponding to the string values of "on" and "off" or disabled, corresponding to the string values of "on" and "off"
Rajesh Kumar, Mohamed Mostafa. 51
respectively. respectively.
The <mfr2> flag indicates whether the transport, in AAL2 type 3 The <mfr2> flag indicates whether the transport, in AAL2 type 3
packets, of MF dialled digits for signaling system R2 is enabled packets, of MF dialled digits for signaling system R2 is enabled
or disabled, corresponding to the string values of "on" and "off" or disabled, corresponding to the string values of "on" and "off"
respectively. respectively.
The <PCMencoding> field indicates whether PCM encoding, if used, The <PCMencoding> field indicates whether PCM encoding, if used,
is based on the A-law or the Mu-law. This can be used to qualify is based on the A-law or the Mu-law. This can be used to qualify
the 'generic PCM' codec stated in some of the AAL2 profiles. The the 'generic PCM' codec stated in some of the AAL2 profiles. The
skipping to change at line 2673 skipping to change at line 2710
5.6.2.14 The 'aal5sscop' attribute 5.6.2.14 The 'aal5sscop' attribute
When present, the 'aal5sscop' attribute is used to indicate the When present, the 'aal5sscop' attribute is used to indicate the
existence of an SSCOP [43] protocol layer over an AAL5 CPS existence of an SSCOP [43] protocol layer over an AAL5 CPS
layer [21], and the parameters which pertain to this SSCOP layer. layer [21], and the parameters which pertain to this SSCOP layer.
SSCOP over AAL5 can also be selected via the aalApp attribute SSCOP over AAL5 can also be selected via the aalApp attribute
defined below. The format of the 'aal5sscop' media attribute defined below. The format of the 'aal5sscop' media attribute
line is as follows: line is as follows:
Rajesh Kumar, Mohamed Mostafa. 53
a=aal5sscop: <fsscopsdu> <bsscopsdu> <fsscopuu> <bsscopuu> a=aal5sscop: <fsscopsdu> <bsscopsdu> <fsscopuu> <bsscopuu>
Each of these fields can be set to a "-" when the intention is to not Each of these fields can be set to a "-" when the intention is to not
specify them in an SDP descriptor. specify them in an SDP descriptor.
The representation, meaning and values of the <fsscopsdu>, <bsscopsdu>, The representation, meaning and values of the <fsscopsdu>, <bsscopsdu>,
<fsscopuu> and <bsscopuu> fields are identical to those for the <fsscopuu> and <bsscopuu> fields are identical to those for the
'aal2sscs3661assured' media attribute line (Section 5.6.2.12). Note that it 'aal2sscs3661assured' media attribute line (Section 5.6.2.12). Note that it
is necessary for the parameters on the 'aal5sscop' media attribute is necessary for the parameters on the 'aal5sscop' media attribute
line to be consistent with each other. line to be consistent with each other.
5.6.3 Service attributes 5.6.3 Service attributes
The following is a summary list of the SDP media attributes that can The following is a summary list of the SDP media attributes that can
be used to describe the services that use the ATM Adaptation Layer (AAL). be used to describe the services that use the ATM Adaptation Layer (AAL).
These attributes are detailed in subsequent subsections. These attributes are detailed in subsequent subsections.
Rajesh Kumar, Mohamed Mostafa. 52
* The 'atmmap' attribute. In the AAL1 and AAL5 contexts, this is * The 'atmmap' attribute. In the AAL1 and AAL5 contexts, this is
used to dynamically map payload types into codec strings. used to dynamically map payload types into codec strings.
* The 'silenceSupp' attribute, used to indicate the use of * The 'silenceSupp' attribute, used to indicate the use of
of voice activity detection for silence suppression, and to of voice activity detection for silence suppression, and to
optionally parameterize the silence suppression function. optionally parameterize the silence suppression function.
* The 'ecanf' and 'ecanb' attributes, used to indicate the use of * The 'ecan' attribute, used to indicate the use of
of echo cancellation, and to parameterize the this function. of echo cancellation, and to parameterize the this function.
* The 'gcf' and 'gcb' attributes, used to indicate the use of * The 'gc' attribute, used to indicate the use of
of gain control, and to parameterize the this function. of gain control, and to parameterize the this function.
* The 'profileDesc' attribute, which can be used to describe * The 'profileDesc' attribute, which can be used to describe
AAL2 profiles. Although any AAL2 profile can be so described, AAL2 profiles. Although any AAL2 profile can be so described,
this attribute is useful for describing, at connection this attribute is useful for describing, at connection
establishment time, custom profiles that might not be known establishment time, custom profiles that might not be known
to the far end. This attribute applies in the AAL2 context to the far end. This attribute applies in the AAL2 context
only. only.
* The 'vsel' attribute, which indicates a prioritized list of * The 'vsel' attribute, which indicates a prioritized list of
skipping to change at line 2725 skipping to change at line 2762
be consistent with it. be consistent with it.
* The 'dsel' attribute, which indicates a prioritized list of * The 'dsel' attribute, which indicates a prioritized list of
3-tuples for voiceband data service. Each 3-tuple indicates a 3-tuples for voiceband data service. Each 3-tuple indicates a
codec, an optional packet length and an optional packetization codec, an optional packet length and an optional packetization
period. This complements the 'm' line information and should period. This complements the 'm' line information and should
be consistent with it. be consistent with it.
* The 'fsel' attribute, which indicates a prioritized list of * The 'fsel' attribute, which indicates a prioritized list of
3-tuples for facsimile service. Each 3-tuple indicates a 3-tuples for facsimile service. Each 3-tuple indicates a
Rajesh Kumar, Mohamed Mostafa. 54
codec, an optional packet length and an optional packetization codec, an optional packet length and an optional packetization
period. This complements the 'm' line information and should period. This complements the 'm' line information and should
be consistent with it. be consistent with it.
* The 'onewaySel' attribute, which indicates a prioritized list of
3-tuples for one direction of an asymmetric connection. Each 3-tuple
indicates a codec, an optional packet length and an
optional packetization period. This complements the 'm'
line information and should be consistent with it.
* The 'codecconfig' attribute, which is used to represent the * The 'codecconfig' attribute, which is used to represent the
contents of the single codec information element (IE) defined contents of the single codec information element (IE) defined
in ITU Q.765.5 [57]. in ITU Q.765.5 [57].
* The 'isup_usi' attribute, which is used to represent * The 'isup_usi' attribute which is used to represent the bearer
capability information element defined in Section 4.5.5 of
ITU Q.931 [59], and reiterated as the user service
information element (IE) in Section 3.57 of ITU Q.763 [60].
* The 'uiLayer1_Prot' attribute, which is used to represent
the 'User Information Layer 1 protocol' field within the the 'User Information Layer 1 protocol' field within the
bearer capability information element defined in Section bearer capability information element defined in Section
4.5.5 of ITU Q.931 [59]. 4.5.5 of ITU Q.931 [59].
5.6.3.1 The 'atmmap' attribute 5.6.3.1 The 'atmmap' attribute
The 'atmmap' attribute is defined on the basis of the 'rtpmap' The 'atmmap' attribute is defined on the basis of the 'rtpmap'
attribute used in RFC2327. attribute used in RFC2327.
Rajesh Kumar, Mohamed Mostafa. 53
a=atmmap:<payloadType> <encodingName> a=atmmap:<payloadType> <encodingName>
The 'atmmap' attribute is used to dynamically map encoding names The 'atmmap' attribute is used to dynamically map encoding names
into payload types. This is necessary for those encoding names which into payload types. This is necessary for those encoding names which
have not been assigned a static payload type through IANA [31]. Payload have not been assigned a static payload type through IANA [31]. Payload
types and encoding techniques that have been registered with IANA types and encoding techniques that have been registered with IANA
for RTP are retained for AAL1 and AAL5. for RTP are retained for AAL1 and AAL5.
The range of statically defined payload types is in the range The range of statically defined payload types is in the range
0-95. All static assignments of payload types to codecs are 0-95. All static assignments of payload types to codecs are
listed in [31]. The range of payload types defined dynamically listed in [31]. The range of payload types defined dynamically
via the 'atmmap' attribute is 96-127. via the 'atmmap' attribute is 96-127.
In addition to reiterating the payload types and encoding In addition to reiterating the payload types and encoding
names in [31], Table 2 defines non-standard encoding names names in [31], Table 2 defines non-standard encoding names
(with "X-" prefixes). Note that [31], rather than Table 2, (with "X-" prefixes). Note that [31], rather than Table 2,
is the authoritative list of standard codec names and payload is the authoritative list of standard codec names and payload
types in the ATM context. types in the ATM context.
Rajesh Kumar, Mohamed Mostafa. 54 Rajesh Kumar, Mohamed Mostafa. 55
Table 2: Encoding Names and Payload Types Table 2: Encoding Names and Payload Types
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| Encoding Technique | Encoding Name| Payload type | | Encoding Technique | Encoding Name| Payload type |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| PCM - Mu law | "PCMU" | 0 (Statically Mapped) | | PCM - Mu law | "PCMU" | 0 (Statically Mapped) |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| 32 kbps ADPCM | "G726-32" | 2 (Statically Mapped) | | 32 kbps ADPCM | "G726-32" | 2 (Statically Mapped) |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
|Dual rate 5.3/6.3kbps| "G723" | 4 (Statically Mapped) | |Dual rate 5.3/6.3kbps| "G723" | 4 (Statically Mapped) |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
skipping to change at line 2815 skipping to change at line 2864
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| Dual rate 5.3/6.3 |"X-G7231-L" | None, map dynamically | | Dual rate 5.3/6.3 |"X-G7231-L" | None, map dynamically |
| kbps - low rate | | | | kbps - low rate | | |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| Dual rate 5.3/6.3 |"X-G7231a-H" | None, map dynamically | | Dual rate 5.3/6.3 |"X-G7231a-H" | None, map dynamically |
| kbps - high rate w/ | | | | kbps - high rate w/ | | |
| ITU-defined silence | | | | ITU-defined silence | | |
| suppression | | | | suppression | | |
|----------------------------------------------------------------| |----------------------------------------------------------------|
Rajesh Kumar, Mohamed Mostafa. 55 Rajesh Kumar, Mohamed Mostafa. 56
+---------------------+--------------+---------------------------+ +---------------------+--------------+---------------------------+
| Dual rate 5.3/6.3 |"X-G7231a-L" | None, map dynamically | | Dual rate 5.3/6.3 |"X-G7231a-L" | None, map dynamically |
| kbps - high rate w/ | | | | kbps - high rate w/ | | |
| ITU-defined silence | | | | ITU-defined silence | | |
| suppression | | | | suppression | | |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| 16 kbps EADPCM | "X-G727-16" | None, map dynamically | | 16 kbps EADPCM | "X-G727-16" | None, map dynamically |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| 24 kbps EADPCM | "X-G727-24" | None, map dynamically | | 24 kbps EADPCM | "X-G727-24" | None, map dynamically |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
skipping to change at line 2869 skipping to change at line 2918
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| L16 [3], Sixteen | "L16" | 11 (Statically Mapped) | | L16 [3], Sixteen | "L16" | 11 (Statically Mapped) |
| Bit Linear PCM, | | | | Bit Linear PCM, | | |
| Single channel | | | | Single channel | | |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| QCELP [3] | "QCELP" | 12 (Statically Mapped) | | QCELP [3] | "QCELP" | 12 (Statically Mapped) |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| MPEG1/MPEG2 audio | "MPA" | 14 (Statically Mapped) | | MPEG1/MPEG2 audio | "MPA" | 14 (Statically Mapped) |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
Rajesh Kumar, Mohamed Mostafa. 56 Rajesh Kumar, Mohamed Mostafa. 57
+---------------------+--------------+---------------------------+ +---------------------+--------------+---------------------------+
| DVI4, 11.025 KHz[3] | "DVI4" | 16 (Statically Mapped) | | DVI4, 11.025 KHz[3] | "DVI4" | 16 (Statically Mapped) |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| DVI4, 22.05 KHz [3] | "DVI4" | 17 (Statically Mapped) | | DVI4, 22.05 KHz [3] | "DVI4" | 17 (Statically Mapped) |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| MPEG1/MPEG2 video | "MPV" | 32 (Statically Mapped) | | MPEG1/MPEG2 video | "MPV" | 32 (Statically Mapped) |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| MPEG 2 audio/video | "MP2T" | 33 (Statically Mapped) | | MPEG 2 audio/video | "MP2T" | 33 (Statically Mapped) |
| transport stream | | | | transport stream | | |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
skipping to change at line 2914 skipping to change at line 2963
| ITU-R Recommendation| "BT656" | None, map dynamically | | ITU-R Recommendation| "BT656" | None, map dynamically |
| BT.656-3 for | | | | BT.656-3 for | | |
| digital video | | | | digital video | | |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| Adaptive Multirate | "FR-AMR" | None, map dynamically | | Adaptive Multirate | "FR-AMR" | None, map dynamically |
|-Full Rate (3GPP)[58]| | | |-Full Rate (3GPP)[58]| | |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| Adaptive Multirate | "HR-AMR" | None, map dynamically | | Adaptive Multirate | "HR-AMR" | None, map dynamically |
|-Half Rate (3GPP)[58]| | | |-Half Rate (3GPP)[58]| | |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| Adaptive Multirate | "HR-UMTS" | None, map dynamically | | Adaptive Multirate | "UMTS-AMR" | None, map dynamically |
|- UMTS(3GPP) [58] | | | |- UMTS(3GPP) [58] | | |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| Adaptive Multirate | "AMR" | None, map dynamically |
|- Generic [58] | | |
|---------------------|--------------|---------------------------|
Rajesh Kumar, Mohamed Mostafa. 57 Rajesh Kumar, Mohamed Mostafa. 58
5.6.3.2 The 'silenceSupp' attribute 5.6.3.2 The 'silenceSupp' attribute
When present, the 'silenceSupp' attribute is used to indicate When present, the 'silenceSupp' attribute is used to indicate
the use or non-use of silence suppression. the use or non-use of silence suppression.
The format of the 'silenceSupp' media attribute line is The format of the 'silenceSupp' media attribute line is
as follows: as follows:
a=silenceSupp: <silenceSuppEnable> <silenceTimer> <suppPref> <sidUse> a=silenceSupp: <silenceSuppEnable> <silenceTimer> <suppPref> <sidUse>
<fxnslevel> <fxnslevel>
skipping to change at line 2968 skipping to change at line 3020
The <sidUse> indicates whether SIDs (Silence Insertion The <sidUse> indicates whether SIDs (Silence Insertion
Descriptors) are to be used, and whether they use fixed comfort Descriptors) are to be used, and whether they use fixed comfort
noise or sampled background noise. It can take on the noise or sampled background noise. It can take on the
string values of "No SID", "Fixed Noise", "Sampled Noise". string values of "No SID", "Fixed Noise", "Sampled Noise".
If the value of <sidUse> is "Fixed Noise", then <fxnslevel> If the value of <sidUse> is "Fixed Noise", then <fxnslevel>
provides its level. It can take on integer values in the range provides its level. It can take on integer values in the range
0-127, as follows: 0-127, as follows:
Rajesh Kumar, Mohamed Mostafa. 58 Rajesh Kumar, Mohamed Mostafa. 59
+-----------------------+---------------------+ +-----------------------+---------------------+
| <fxnslevel> value | Meaning | | <fxnslevel> value | Meaning |
+-----------------------+---------------------+ +-----------------------+---------------------+
| 0-29 | Reserved | | 0-29 | Reserved |
| 30 | -30 dBm0 | | 30 | -30 dBm0 |
| 31 | -31 dBm0 | | 31 | -31 dBm0 |
| . . . | . . . | | . . . | . . . |
| 77 | -77 dBm0 | | 77 | -77 dBm0 |
| 78 | -78 dBm0 | | 78 | -78 dBm0 |
| 79-126 | reserved | | 79-126 | reserved |
| 127 | Idle Code (no noise)| | 127 | Idle Code (no noise)|
+-----------------------+---------------------+ +-----------------------+---------------------+
In addition to the decimal representation of <fxnslevel>, a In addition to the decimal representation of <fxnslevel>, a
hex representation, preceded by a "0x" prefix, is also allowed. hex representation, preceded by a "0x" prefix, is also allowed.
5.6.3.3 The 'ecanf' and 'ecanb' attributes 5.6.3.3 The 'ecan' attribute
When present, the 'ecanf' and 'ecanb' attributes are used to indicate When present, the 'ecan' attribute s is used to indicate
the use or non-use of echo cancellation in the forward the use or non-use of echo cancellation. There can be several
and backward directions respectively. See Section 'ecan' lines in an SDP description.
2.3 for a definition of the terms 'forward' and 'backward'.
The format of the 'ecanf' and 'ecanb' media attribute lines is The format of the 'ecan' media attribute line is
as follows: as follows:
a=ecanf: <ecanEnable> <ecanType> a=ecan:<directionFlag><ecanEnable><ecanType>
a=ecanb: <ecanEnable> <ecanType>
If any of the parameters in the ecanf and ecanb media attribute lines The <directionFlag> can be assigned the following string values: "f",
is not specified, is inapplicable or is implied, then it is set to "b" and "fb". "f" and "b" indicate the forward and backward
"-". directions respectively. "fb" refers to both directions (forward and
backward). Conventions for the forward and backward directions
are per section 2.3.
If the 'ecanf' or 'ecanb' media attribute lines is not present, The <directionFlag> is always specified. Except for the <directionFlag>,
the remaining parameters can be set to "-" to indicate that they are
not specified, inapplicable or implied. However, there must be some
specified parameters for the line to be useful in an SDP description.
If the 'ecan' media attribute lines is not present,
then means other than the SDP descriptor must be used to determine then means other than the SDP descriptor must be used to determine
the applicability and nature of echo cancellation in that direction. the applicability and nature of echo cancellation for a connection
Examples of such means are MIB provisioning, the local connection options direction. Examples of such means are MIB provisioning, the local
structure in MGCP etc. connection options structure in MGCP etc.
The <ecanEnable> parameter can take on values of "on" or "off". If it The <ecanEnable> parameter can take on values of "on" or "off". If it
is "on", then echo cancellation is enabled. If it is "off", is "on", then echo cancellation is enabled. If it is "off",
then echo cancellation is disabled. then echo cancellation is disabled.
The <ecanType> parameter can take on the string values "G165" and "G168" The <ecanType> parameter can take on the string values "G165" and "G168"
Rajesh Kumar, Mohamed Mostafa. 60
respectively. respectively.
When SDP is used with some media gateway control protocols such as MGCP When SDP is used with some media gateway control protocols such as MGCP
and Megaco [26], there exist means outside SDP descriptions to specify and Megaco [26], there exist means outside SDP descriptions to specify
the echo cancellation properties of a connection. Nevertheless, this the echo cancellation properties of a connection. Nevertheless, this
media attribute line is included for completeness. As a result, the media attribute line is included for completeness. As a result, the
SDP can be used for describing echo cancellation in applications SDP can be used for describing echo cancellation in applications
where alternate means for this are unavailable. where alternate means for this are unavailable.
Rajesh Kumar, Mohamed Mostafa. 59 5.6.3.4 The 'gc' attributes
5.6.3.4 The 'gcf' and 'gcb' attributes
When present, the 'gcf' and 'gcb' attributes are used to indicate When present, the 'gc' attribute is used to indicate
the use or non-use of gain control in the forward and backward the use or non-use of gain control. There can be several
directions respectively. See Section 2.3 for a definition of the 'gc' lines in an SDP description.
terms 'forward' and 'backward'.
The format of the 'gcf' and 'gcb' media attribute lines is as The format of the 'gc' media attribute line is as
follows: follows:
a=gcf: <gcEnable> <gcLvl> a=gc:<directionFlag><gcEnable><gcLvl>
a=gcb: <gcEnable> <gcLvl>
If any of the parameters in the gcf and gcb media attribute lines The <directionFlag> can be assigned the following string values: "f",
is not specified, is inapplicable or is implied, then it is set to "b" and "fb". "f" and "b" indicate the forward and backward
"-". If the 'gcf' or 'gcb' media attribute line is not present, directions respectively. "fb" refers to both directions (forward and
then means other than the SDP descriptor must be used to determine the backward). Conventions for the forward and backward directions
applicability and nature of gain control in that direction. Examples of such are per section 2.3.
means are MIB provisioning, the local connection options structure in MGCP
etc. The <directionFlag> is always specified. Except for the <directionFlag>,
the remaining parameters can be set to "-" to indicate that they are
not specified, inapplicable or implied. However, there must be some
specified parameters for the line to be useful in an SDP description.
If the 'gc' media attribute lines is not present,
then means other than the SDP descriptor must be used to determine
the applicability and nature of gain control for a connection
direction. Examples of such means are MIB provisioning, the local
connection options structure in MGCP etc.
The <gcEnable> parameter can take on values of "on" or "off". If it The <gcEnable> parameter can take on values of "on" or "off". If it
is "on", then gain control is enabled. If it is "off", then is "on", then gain control is enabled. If it is "off", then
gain control is disabled. gain control is disabled.
The <gcLvl> parameter is represented as the decimal or hex The <gcLvl> parameter is represented as the decimal or hex
equivalent of a 16-bit binary field. A value of 0xFFFF implies equivalent of a 16-bit binary field. A value of 0xFFFF implies
automatic gain control. Otherwise, this number indicates the automatic gain control. Otherwise, this number indicates the
number of decibels of inserted loss. The upper bound, 65,535 dB number of decibels of inserted loss. The upper bound, 65,535 dB
(0xFFFE) of inserted loss, is an absurdly large number and is a (0xFFFE) of inserted loss, is a large number and is a
carryover from Megaco [26]. In practical applications, the inserted loss carryover from Megaco [26]. In practical applications, the inserted loss
is much lower. is much lower.
When SDP is used with some media gateway control protocols such as MGCP When SDP is used with some media gateway control protocols such as MGCP
and Megaco [26], there exist means outside SDP descriptions to specify and Megaco [26], there exist means outside SDP descriptions to specify
the gain control properties of a connection. Nevertheless, this the gain control properties of a connection. Nevertheless, this
Rajesh Kumar, Mohamed Mostafa. 61
media attribute line is included for completeness. As a result, the media attribute line is included for completeness. As a result, the
SDP can be used for describing gain control in applications SDP can be used for describing gain control in applications
where alternate means for this are unavailable. where alternate means for this are unavailable.
5.6.3.5 The 'profileDesc' attribute 5.6.3.5 The 'profileDesc' attribute
There is one 'profileDesc' media attribute line for each AAL2 There is one 'profileDesc' media attribute line for each AAL2
profile that is intended to be described. The 'profileDesc' media profile that is intended to be described. The 'profileDesc' media
attribute line is structured as follows: attribute line is structured as follows:
a=profileDesc: <aal2transport> <profile> <uuiCodeRange#1> a=profileDesc: <aal2transport> <profile> <uuiCodeRange#1>
<encodingName#1> <packetLength#1> <packetTime#1> <encodingName#1> <packetLength#1> <packetTime#1>
<uuiCodeRange#2> <encodingName#2> <packetLength#2> <uuiCodeRange#2> <encodingName#2> <packetLength#2>
<packetTime#2>... <uuiCodeRange#N> <encodingName#N> <packetTime#2>... <uuiCodeRange#N> <encodingName#N>
<packetLength#N> <packetTime#N> <packetLength#N> <packetTime#N>
Rajesh Kumar, Mohamed Mostafa. 60
Here, <aal2transport> can have those values of <transport> (Table 1) that Here, <aal2transport> can have those values of <transport> (Table 1) that
pertain to AAL2. These are: pertain to AAL2. These are:
AAL2/ATMF AAL2/ATMF
AAL2/ITU AAL2/ITU
AAL2/custom AAL2/custom
AAL2/<corporateName> AAL2/<corporateName>
AAL2/IEEE:<oui> AAL2/IEEE:<oui>
The parameter <profile> is identical to its definition for the 'm' The parameter <profile> is identical to its definition for the 'm'
skipping to change at line 3112 skipping to change at line 3177
The <packetLength> is a decimal integer representation of the AAL2 The <packetLength> is a decimal integer representation of the AAL2
packet length in octets. packet length in octets.
The <packetTime> is a decimal integer representation of the AAL2 The <packetTime> is a decimal integer representation of the AAL2
packetization interval in microseconds. packetization interval in microseconds.
For instance, the 'profileDesc' media attribute line below defines For instance, the 'profileDesc' media attribute line below defines
the AAL2/custom 100 profile. This profile is reproduced in the Table 3 the AAL2/custom 100 profile. This profile is reproduced in the Table 3
below. For a description of the parameters in this profile such as below. For a description of the parameters in this profile such as
Rajesh Kumar, Mohamed Mostafa. 62
M and the sequence number interval, see ITU I.366.2 [13]. M and the sequence number interval, see ITU I.366.2 [13].
a=profileDesc:AAL2/custom 100 0-7 PCMG 40 5000 0-7 SIDG 1 5000 8-15 a=profileDesc:AAL2/custom 100 0-7 PCMG 40 5000 0-7 SIDG 1 5000 8-15
G726-32 40 10000 8-15 SIDG 1 5000 G726-32 40 10000 8-15 SIDG 1 5000
If the <packetTime> parameter is to be omitted or implied, then the If the <packetTime> parameter is to be omitted or implied, then the
same profile can be represented as follows: same profile can be represented as follows:
a=profileDesc:AAL2/custom 100 0-7 PCMG 40 - 0-7 SIDG 1 - 8-15 a=profileDesc:AAL2/custom 100 0-7 PCMG 40 - 0-7 SIDG 1 - 8-15
G726-32 40 - 8-15 SIDG 1 - G726-32 40 - 8-15 SIDG 1 -
If a gateway has a provisioned or hard coded definition of a If a gateway has a provisioned or hard coded definition of a
profile, then any definition provided via the 'profileDesc' line profile, then any definition provided via the 'profileDesc' line
overrides it. The exception to this rule is with regard to standard overrides it. The exception to this rule is with regard to standard
profiles such as ITU-defined profiles and ATMF-defined profiles. In profiles such as ITU-defined profiles and ATMF-defined profiles. In
Rajesh Kumar, Mohamed Mostafa. 61
general, these should not be defined via a 'profileDesc' media general, these should not be defined via a 'profileDesc' media
attribute line. If they are, then the definition needs to be attribute line. If they are, then the definition needs to be
consistent with the standard definition else the SDP session consistent with the standard definition else the SDP session
descriptor should be rejected with an appropriate error code. descriptor should be rejected with an appropriate error code.
Table 3: Example of a custom AAL2 profile Table 3: Example of a custom AAL2 profile
|---------------------------------------------------------------| |---------------------------------------------------------------|
| UUI | Packet |Encoding | | |Packet|Seq.No. | | UUI | Packet |Encoding | | |Packet|Seq.No. |
| Code | Length |per ITU |Description of | M |Time |Interval| | Code | Length |per ITU |Description of | M |Time |Interval|
|point |(octets)|I.366.2 | Algorithm | |(ms) |(ms) | |point |(octets)|I.366.2 | Algorithm | |(ms) |(ms) |
skipping to change at line 3162 skipping to change at line 3227
| | | I-1 | | | | | | | | I-1 | | | | |
|------|--------|---------|---------------|-----|------|--------| |------|--------|---------|---------------|-----|------|--------|
5.6.3.6 The 'vsel' attribute 5.6.3.6 The 'vsel' attribute
The 'vsel' attribute indicates a prioritized list of one or more The 'vsel' attribute indicates a prioritized list of one or more
3-tuples for voice service. Each 3-tuple indicates a codec, an optional 3-tuples for voice service. Each 3-tuple indicates a codec, an optional
packet length and an optional packetization period. This complements the 'm' packet length and an optional packetization period. This complements the 'm'
line information and should be consistent with it. line information and should be consistent with it.
The 'vsel' attribute refers to all directions of a connection.
For a bidirectional connection, these are the forward and backward
directions. For a unidirectional connection, this can be either the
Rajesh Kumar, Mohamed Mostafa. 63
backward or forward direction.
The 'vsel' attribute is not meant to be used with bidirectional
connections that have asymmetric codec configurations
described in a single SDP descriptor. For these, the
'onewaySel' attribute (section 5.6.3.9) should be used. See section 5.6.3.9
for the requirement to not use the 'vsel' and 'onewaySel' attributes
in the same SDP descriptor.
The 'vsel' line is structured as follows: The 'vsel' line is structured as follows:
a=vsel:<encodingName #1> <packetLength #1><packetTime #1> a=vsel:<encodingName #1> <packetLength #1><packetTime #1>
<encodingName #2> <packetLength #2><packetTime #2> <encodingName #2> <packetLength #2><packetTime #2>
... ...
<encodingName #N> <packetLength #N><packetTime #N> <encodingName #N> <packetLength #N><packetTime #N>
where the <encodingName> parameter can take one of the values in column 2 of where the <encodingName> parameter can take one of the values in column 2 of
Table 2. The <packetLength> is a decimal integer representation of the Table 2. The <packetLength> is a decimal integer representation of the
packet length in octets. The <packetTime> is a decimal integer packet length in octets. The <packetTime> is a decimal integer
representation of the packetization interval in microseconds. The parameters representation of the packetization interval in microseconds. The parameters
<packetLength>and <packetTime> can be set to "-" when not needed. Also, the <packetLength> and <packetTime> can be set to "-" when not needed. Also,
entire 'vsel' media attribute line can be omitted when not needed. the entire 'vsel' media attribute line can be omitted when not needed.
For example, For example,
a=vsel:G729 10 10000 G726-32 40 10000 a=vsel:G729 10 10000 G726-32 40 10000
Rajesh Kumar, Mohamed Mostafa. 62
indicates first preference of G.729 or G.729a (both are interoperable) as indicates first preference of G.729 or G.729a (both are interoperable) as
the voice encoding scheme. A packet length of 10 octets and a packetization the voice encoding scheme. A packet length of 10 octets and a packetization
interval of 10 ms are associated with this codec. G726-32 is the second interval of 10 ms are associated with this codec. G726-32 is the second
preference stated in this line, with an associated packet length of 40 preference stated in this line, with an associated packet length of 40
octets and a packetization interval of 10 ms. If the packet length and octets and a packetization interval of 10 ms. If the packet length and
packetization interval are intended to be omitted, then this media attribute packetization interval are intended to be omitted, then this media attribute
line becomes line becomes
a=vsel:G729 - - G726-32 - - a=vsel:G729 - - G726-32 - -
skipping to change at line 3207 skipping to change at line 3284
This media attribute line can be used in ATM as well as non-ATM contexts. This media attribute line can be used in ATM as well as non-ATM contexts.
Within the ATM context, it can be applied to the AAL1, AAL2 and AAL5 Within the ATM context, it can be applied to the AAL1, AAL2 and AAL5
adaptations. The <packetLength> and <packetTime> are not meaningful adaptations. The <packetLength> and <packetTime> are not meaningful
in the AAL1 case and should be set to "-". In the AAL2 case, in the AAL1 case and should be set to "-". In the AAL2 case,
this line determines the use of some or all of the rows in this line determines the use of some or all of the rows in
a given profile table. If multiple 3-tuples are present, they a given profile table. If multiple 3-tuples are present, they
can indicate a hierarchical assignment of some rows in that can indicate a hierarchical assignment of some rows in that
profile to voice service e.g. row A preferred to row B etc. profile to voice service e.g. row A preferred to row B etc.
If multiple profiles are present on the 'm' line, the profile If multiple profiles are present on the 'm' line, the profile
Rajesh Kumar, Mohamed Mostafa. 64
qualified by this attribute is the first qualified by this attribute is the first
profile. If a single profile that has been selected for a connection profile. If a single profile that has been selected for a connection
is indicated in the 'm' line, the 'vsel' attribute qualifies the is indicated in the 'm' line, the 'vsel' attribute qualifies the
use, for voice service, of codecs within that profile. use, for voice service, of codecs within that profile.
With most of the encoding names in Figure 2, the packet length With most of the encoding names in Figure 2, the packet length
and packetization period can be derived from each other. One of them and packetization period can be derived from each other. One of them
can be set to "-" without a loss of information. There are some can be set to "-" without a loss of information. There are some
exceptions such as the IANA-registered encoding names G723, DVI4 and exceptions such as the IANA-registered encoding names G723, DVI4 and
L16 for which this is not true. Therefore, there is a need to L16 for which this is not true. Therefore, there is a need to
skipping to change at line 3233 skipping to change at line 3312
one or more 3-tuples for voiceband data service. The <fxIncl> one or more 3-tuples for voiceband data service. The <fxIncl>
flag indicates whether this definition of voiceband data flag indicates whether this definition of voiceband data
includes fax ("on" value) or not ("off" value). If <fxIncl> is includes fax ("on" value) or not ("off" value). If <fxIncl> is
"on", then the 'dsel' line must be consistent with any 'fsel' line "on", then the 'dsel' line must be consistent with any 'fsel' line
in the session description. In this case, an error event is generated in the session description. In this case, an error event is generated
in the case of inconsistency. Each 3-tuple indicates a codec, in the case of inconsistency. Each 3-tuple indicates a codec,
an optional packet length and an optional packetization an optional packet length and an optional packetization
period. This complements the 'm' line information and should period. This complements the 'm' line information and should
be consistent with it. be consistent with it.
Rajesh Kumar, Mohamed Mostafa. 63 The 'dsel' attribute refers to all directions of a connection.
For a bidirectional connection, these are the forward and backward
directions. For a unidirectional connection, this can be either the
backward or forward direction.
The 'dsel' attribute is not meant to be used with bidirectional
connections that have asymmetric codec configurations
described in a single SDP descriptor. For these, the
'onewaySel' attribute (section 5.6.3.9) should be used. See section 5.6.3.9
for the requirement to not use the 'dsel' and 'onewaySel' attributes
in the same SDP descriptor.
The 'dsel' line is structured as follows: The 'dsel' line is structured as follows:
a=dsel:<fxIncl> <encodingName #1> <packetLength #1><packetTime #1> a=dsel:<fxIncl> <encodingName #1> <packetLength #1><packetTime #1>
<encodingName #2> <packetLength #2><packetTime #2> <encodingName #2> <packetLength #2><packetTime #2>
... ...
<encodingName #N> <packetLength #N><packetTime #N> <encodingName #N> <packetLength #N><packetTime #N>
where the <encodingName> parameter can take one of the values in where the <encodingName> parameter can take one of the values in
column 2 of Table 2. The <packetLength> and <packetTime> column 2 of Table 2. The <packetLength> and <packetTime>
parameters are per their definition, above, for the 'vsel' parameters are per their definition, above, for the 'vsel'
media attribute line. The parameters <packetLength>and <packetTime>) media attribute line. The parameters <packetLength>and <packetTime>)
can be set to "-" when not needed. The <fxIncl> flag is presumed to be can be set to "-" when not needed. The <fxIncl> flag is presumed to be
"off" if it is set to "-". Also, the entire 'dsel' media attribute line "off" if it is set to "-". Also, the entire 'dsel' media attribute line
can be omitted when not needed. can be omitted when not needed.
Rajesh Kumar, Mohamed Mostafa. 65
For example, For example,
a=dsel:- G726-32 20 5000 PCMU 40 5000 a=dsel:- G726-32 20 5000 PCMU 40 5000
indicates that this line does not address facsimile, and that the indicates that this line does not address facsimile, and that the
first preference for the voiceband data codes is 32 kbps ADPCM, first preference for the voiceband data codes is 32 kbps ADPCM,
while the second preference is PCMU. The packet length while the second preference is PCMU. The packet length
and the packetization interval associated with G726-32 are 20 octets and and the packetization interval associated with G726-32 are 20 octets and
5 ms respectively. For PCMU, they are 40 octets and 5 ms respectively. 5 ms respectively. For PCMU, they are 40 octets and 5 ms respectively.
skipping to change at line 3286 skipping to change at line 3377
exceptions such as the IANA-registered encoding names G723, DVI4 and exceptions such as the IANA-registered encoding names G723, DVI4 and
L16 for which this is not true. Therefore, there is a need to L16 for which this is not true. Therefore, there is a need to
retain both the packet length and packetization period in the retain both the packet length and packetization period in the
definition of the 'dsel' line. definition of the 'dsel' line.
5.6.3.8 The 'fsel' attribute 5.6.3.8 The 'fsel' attribute
The 'fsel' attribute indicates a prioritized list of The 'fsel' attribute indicates a prioritized list of
one or more 3-tuples for facsimile service. If an 'fsel' line one or more 3-tuples for facsimile service. If an 'fsel' line
is present, any 'dsel' line with <fxIncl> set to "on" in the session is present, any 'dsel' line with <fxIncl> set to "on" in the session
Rajesh Kumar, Mohamed Mostafa. 64
description must be consistent with it. In this case, description must be consistent with it. In this case,
an error event is generated in the case of inconsistency. an error event is generated in the case of inconsistency.
Each 3-tuple indicates a codec, an optional packet length and an Each 3-tuple indicates a codec, an optional packet length and an
optional packetization period. This complements the 'm' line information optional packetization period. This complements the 'm' line information
and should be consistent with it. and should be consistent with it.
The 'fsel' attribute refers to all directions of a connection.
For a bidirectional connection, these are the forward and backward
directions. For a unidirectional connection, this can be either the
backward or forward direction.
The 'fsel' attribute is not meant to be used with bidirectional
connections that have asymmetric codec configurations described in a
single SDP descriptor. For these, the 'onewaySel' attribute
Rajesh Kumar, Mohamed Mostafa. 66
(section 5.6.3.9) should be used. See section 5.6.3.9 for the
requirement to not use the 'fsel' and 'onewaySel' attributes in the
same SDP descriptor.
The 'fsel' line is structured as follows: The 'fsel' line is structured as follows:
a=fsel:<encodingName #1> <packetLength #1><packetTime #1> a=fsel:<encodingName #1> <packetLength #1><packetTime #1>
<encodingName #2> <packetLength #2><packetTime #2> <encodingName #2> <packetLength #2><packetTime #2>
... ...
<encodingName #N> <packetLength #N><packetTime #N> <encodingName #N> <packetLength #N><packetTime #N>
where the <encodingName> parameter can take one of the values in where the <encodingName> parameter can take one of the values in
column 2 of Table 2. The <packetLength> and <packetTime> column 2 of Table 2. The <packetLength> and <packetTime>
parameters are per their definition, above, for the 'vsel' parameters are per their definition, above, for the 'vsel'
skipping to change at line 3339 skipping to change at line 3442
profile to facsimile service e.g. row A preferred to row B etc. profile to facsimile service e.g. row A preferred to row B etc.
If multiple profiles are present on the 'm' line, the profile If multiple profiles are present on the 'm' line, the profile
qualified by this attribute is the first qualified by this attribute is the first
profile. If a single profile that has been selected for a connection profile. If a single profile that has been selected for a connection
is indicated in the 'm' line, the 'fsel' attribute qualifies the is indicated in the 'm' line, the 'fsel' attribute qualifies the
use, for facsimile service, of codecs within that profile. use, for facsimile service, of codecs within that profile.
With most of the encoding names in Figure 2, the packet length With most of the encoding names in Figure 2, the packet length
and packetization period can be derived from each other. One of them and packetization period can be derived from each other. One of them
can be set to "-" without a loss of information. There are some can be set to "-" without a loss of information. There are some
Rajesh Kumar, Mohamed Mostafa. 65
exceptions such as the IANA-registered encoding names G723, DVI4 and exceptions such as the IANA-registered encoding names G723, DVI4 and
L16 for which this is not true. Therefore, there is a need to L16 for which this is not true. Therefore, there is a need to
Rajesh Kumar, Mohamed Mostafa. 67
retain both the packet length and packetization period in the retain both the packet length and packetization period in the
definition of the 'fsel' line. definition of the 'fsel' line.
5.6.3.9 The 'codecconfig' attribute 5.6.3.9 The 'onewaySel' attribute
The 'onewaySel' (one way select) attribute can be used
with connections that have asymmetric codec configurations.
There can be several 'onewaySel' lines in an SDP description.
The 'onewaySel' line is structured as follows:
a=onewaySel:<serviceType> <directionFlag>
<encodingName #1> <packetLength #1><packetTime #1>
<encodingName #2> <packetLength #2><packetTime #2>
...
<encodingName #N> <packetLength #N><packetTime #N>
The <serviceType> parameter can be assigned the following string values:
"v", "d", "f", "df" and "all". These indicate voice, voiceband data
(fax not included), fax, voiceband data (fax included) and
all services respectively.
The <directionFlag> can be assigned the following string values: "f",
"b" and "fb". "f" and "b" indicate the forward and backward
directions respectively. "fb" refers to both directions (forward and
backward) and shall not be used with the 'onewaySel' line. Conventions
for the forward and backward directions are per section 2.3.
Following <directionFlag>, there is a prioritized list of one or more
3-tuples. Each 3-tuple indicates a codec, an optional
packet length and an optional packetization period. This complements the 'm'
line information and should be consistent with it.
Within each 3-tuple, the <encodingName> parameter can take one of
the values in column 2 of Table 2. The <packetLength> is a decimal
integer representation of the packet length in octets. The <packetTime>
is a decimal integer representation of the packetization
interval in microseconds.
The 'onewaySel' attribute must not be used in SDP descriptors that have
one or more of the following attributes: 'vsel', 'dsel', 'fsel'. If it is
present, then command containing the SDP description may be rejected. An
alternate response to such an ill-formed SDP descriptor might the selective
ignoring of some attributes, which must be coordinated
via an application-wide policy.
The <serviceType>, <directionFlag> and <encodingName> parameters may
not be set to "-". However, the parameters <packetLength> and
<packetTime> can be set to "-" when not needed.
For example,
a=onewaySel:v f G729 10 10000
Rajesh Kumar, Mohamed Mostafa. 68
a=onewaySel:v b G726-32 40 10000
indicates that for voice service, the codec to be used in the forward
direction is G.729 or G.729a (both are interoperable), and the codec to
be used in the backward direction is G726-32. A packet length of
10 octets and a packetization interval of 10 ms are associated with
the G.729/G.729a codec. A packet length of 40 octets and a
packetization interval of 10 ms are associated with the G726-32 codec.
For example,
a=onewaySel:d f G726-32 20 5000
a=onewaySel:d b PCMU 40 5000
indicates that for voiceband service (fax not included), the codec to be
used in the forward direction is G726-32), and the codec to
be used in the backward direction is PCMU. A packet length of
20 octets and a packetization interval of 5 ms are associated with
the G726-32 codec. A packet length of 40 octets and a
packetization interval of 5 ms are associated with the PCMU codec.
This media attribute line can be used in ATM as well as non-ATM contexts.
Within the ATM context, it can be applied to the AAL1, AAL2 and AAL5
adaptations. The <packetLength> and <packetTime> are not meaningful
in the AAL1 case and should be set to "-". In the AAL2 case,
these lines determine the use of some or all of the rows in
a given profile table. If multiple 3-tuples are present, they
can indicate a hierarchical assignment of some rows in that
profile to voice service e.g. row A preferred to row B etc.
If multiple profiles are present on the 'm' line, the profile
qualified by this attribute is the first
profile.
With most of the encoding names in Figure 2, the packet length
and packetization period can be derived from each other. One of them
can be set to "-" without a loss of information. There are some
exceptions such as the IANA-registered encoding names G723, DVI4 and
L16 for which this is not true. Therefore, there is a need to
retain both the packet length and packetization period in the
definition of the 'onewaySel' line.
5.6.3.10 The 'codecconfig' attribute
When present, the 'codecconfig' attribute is used to represent the When present, the 'codecconfig' attribute is used to represent the
contents of the single codec information element (IE) defined in [57]. contents of the single codec information element (IE) defined in [57].
The contents of this IE are: a single-octet Organizational Identifier The contents of this IE are: a single-octet Organizational Identifier
(OID) field, followed by a single-octet Codec Type field, followed by (OID) field, followed by a single-octet Codec Type field, followed by
zero or more octets of a codec configuration bit-map. The semantics of zero or more octets of a codec configuration bit-map. The semantics of
the codec configuration bit-map are specific to the organization the codec configuration bit-map are specific to the organization
[57, 58]. The 'codecconfig' attribute is represented as follows: [57, 58]. The 'codecconfig' attribute is represented as follows:
a=codecconfig:<q7655scc> a=codecconfig:<q7655scc>
Rajesh Kumar, Mohamed Mostafa. 69
The <q7655scc> (Q.765.5 single codec IE contents) parameter is The <q7655scc> (Q.765.5 single codec IE contents) parameter is
represented as a string of hex digits. The number of hex digits is represented as a string of hex digits. The number of hex digits is
even (range 4 -32). The "0x" prefix shall be omitted since this value even (range 4 -32). The "0x" prefix shall be omitted since this value
is always hexadecimal. As with other hex values [Section 2.2], is always hexadecimal. As with other hex values [Section 2.2],
digits to the left are more significant than digits to the right. digits to the left are more significant than digits to the right.
Leading zeros shall not be omitted. Leading zeros shall not be omitted.
An example of the use of this media attribute is: An example of the use of this media attribute is:
a=codecconfig:01080C a=codecconfig:01080C
The first octet indicates an Organizational Identifier of 0x01 The first octet indicates an Organizational Identifier of 0x01
(the ITU-T). Using ITU Q.765.5 [57], the second octet (0x08) indicates (the ITU-T). Using ITU Q.765.5 [57], the second octet (0x08) indicates
a codec type of G.726 (ADPCM). The last octet, 0x0C indicates that a codec type of G.726 (ADPCM). The last octet, 0x0C indicates that
16 kbps and 24 kbps rates are NOT supported, while the 32 kbps and 16 kbps and 24 kbps rates are NOT supported, while the 32 kbps and
40 kbps rates ARE supported. 40 kbps rates ARE supported.
5.6.3.10 The 'isup_usi' attribute 5.6.3.11 The 'isup_usi' attribute
When present, the 'isup_usi' attribute is used to represent the When present, the 'isup_usi' attribute is used to represent the bearer
capability information element defined in Section 4.5.5 of ITU Q.931[59]
(excluding the information element identifier and length). This information
element is reiterated as the user service information element (IE)
in Section 3.57 of ITU Q.763 [60]. The 'isup_usi' attribute is
represented as follows:
a=isup_usi:<isupUsi>
The <isupUsi> parameter is represented as a string of hex
digits. The number of hex digits is even (allowed range 4 -24).
The "0x" prefix shall be omitted since this value
is always hexadecimal. As with other hex values [Section 2.2],
digits to the left are more significant than digits to the right.
Leading zeros shall not be omitted.
5.6.3.12 The 'uiLayer1_Prot' attribute
When present, the 'uiLayer1_Prot' attribute is used to represent the
'User Information Layer 1 protocol' field within the bearer 'User Information Layer 1 protocol' field within the bearer
capability information element defined in Section 4.5.5 of [59], and capability information element defined in Section 4.5.5 of [59], and
reiterated as the user service information element (IE) in Section 3.57 reiterated as the user service information element (IE) in Section 3.57
of [60]. The 'User Information Layer 1 protocol' field consists of of [60]. The 'User Information Layer 1 protocol' field consists of
the five least significant bits of Octet 5 of this information the five least significant bits of Octet 5 of this information
element. This field is represented by the USI property in Section C.9 element.
of the Megaco/H.248 protocol [26].
Within SDP, the 'isup_usi' attribute is represented as follows: Within SDP, the 'uiLayer1_Prot' attribute is represented as follows:
a=isup_usi:<isupUsi> a='uiLayer1_Prot':<uiLayer1Prot>
The <isupUsi> parameter is represented as a string of two hex The <uiLayer1Prot> parameter is represented as a string of two hex
digits. The "0x" prefix shall be omitted since this value digits. The "0x" prefix shall be omitted since this value
is always hexadecimal. As with other hex values [Section 2.2],
Rajesh Kumar, Mohamed Mostafa. 66 Rajesh Kumar, Mohamed Mostafa. 70
is always hexadecimal. As with other hex values [Section 2.2],
digits to the left are more significant than digits to the right. digits to the left are more significant than digits to the right.
These hex digits are constructed from an octet with three leading These hex digits are constructed from an octet with three leading
'0' bits and last five bits equal to the 'User Information Layer '0' bits and last five bits equal to the 'User Information Layer
1 protocol' field described above. As specified in [59] and [26], 1 protocol' field described above. As specified in [59] and [26],
bit 5 of this field is the most significant bit. The resulting values bit 5 of this field is the most significant bit. The resulting values
of the <isupUsi> parameter are as follows: of the <uiLayer1Prot> parameter are as follows:
VALUE MEANING VALUE MEANING
0x01 CCITT standardized rate adaption V.110 and X.30 0x01 CCITT standardized rate adaption V.110 and X.30
0x02 Recommendation G.711 Mu-law 0x02 Recommendation G.711 Mu-law
0x03 Recommendation G.711 A-law 0x03 Recommendation G.711 A-law
0x04 Recommendation G.721 32 kbps ADPCM and Recommendation I.460 0x04 Recommendation G.721 32 kbps ADPCM and Recommendation I.460
0x05 Recommendations H.221 and H.242 0x05 Recommendations H.221 and H.242
0x06 Recommendation H.223 and H.245 0x06 Recommendation H.223 and H.245
0x07 Non-ITU-T standardized rate adaption 0x07 Non-ITU-T standardized rate adaption
0x08 ITU-T standardized rate adaption V.120 0x08 ITU-T standardized rate adaption V.120
skipping to change at line 3445 skipping to change at line 3658
Chaining averts the need to set up a single SDP description for a Chaining averts the need to set up a single SDP description for a
session that is simultaneously created at multiple layers. It allows session that is simultaneously created at multiple layers. It allows
the SDP descriptors for different layers to remain simple and clean. the SDP descriptors for different layers to remain simple and clean.
Chaining is not needed in the Megaco context, where it is possible to Chaining is not needed in the Megaco context, where it is possible to
create separate terminations for the different layers of a connection. create separate terminations for the different layers of a connection.
The 'chain' media attribute line has the following format: The 'chain' media attribute line has the following format:
a=chain:<chainPointer> a=chain:<chainPointer>
Rajesh Kumar, Mohamed Mostafa. 67 Rajesh Kumar, Mohamed Mostafa. 71
The <chainPointer> field can take on the following string values: The <chainPointer> field can take on the following string values:
"NEXT", "PREVIOUS" and "NULL". The value "NULL" is not equivalent to "NEXT", "PREVIOUS" and "NULL". The value "NULL" is not equivalent to
omitting the chain attribute from a description since it expressly omitting the chain attribute from a description since it expressly
precludes the possibility of chaining. If the 'chain' attribute is precludes the possibility of chaining. If the 'chain' attribute is
absent in an SDP description, chaining can still be realized by the absent in an SDP description, chaining can still be realized by the
presence of a chain media attribute line in the previous or next presence of a chain media attribute line in the previous or next
description. description.
5.6.5 Use of the second media-level part in H.323 Annex C applications 5.6.5 Use of the second media-level part in H.323 Annex C applications
skipping to change at line 3492 skipping to change at line 3705
This informative section supplements the definition of the eecid This informative section supplements the definition of the eecid
attribute (Section 5.6.1.1) by describing example procedures for its use. attribute (Section 5.6.1.1) by describing example procedures for its use.
These procedures assume a bearer-signaling mechanism for connection set-up These procedures assume a bearer-signaling mechanism for connection set-up
that is independent of service-level call control. These procedures are that is independent of service-level call control. These procedures are
independent of the media gateway control protocol (MGCP, Megaco, SIP etc.), independent of the media gateway control protocol (MGCP, Megaco, SIP etc.),
the protocol used between media gateway controllers (ITU Q.1901, SIP the protocol used between media gateway controllers (ITU Q.1901, SIP
etc.) and the protocol used for bearer connection set-up (Q.2931, UNI, PNNI, etc.) and the protocol used for bearer connection set-up (Q.2931, UNI, PNNI,
AINI, IISP, Q.2630.1 etc.). AINI, IISP, Q.2630.1 etc.).
Rajesh Kumar, Mohamed Mostafa. 68 Rajesh Kumar, Mohamed Mostafa. 72
Inter-MGC Inter-MGC
+---------+ Protocol +---------+ +---------+ Protocol +---------+
| MGC |------------------| MGC | | MGC |------------------| MGC |
+---------+ +---------+ +---------+ +---------+
| | | |
|Media Gateway |Media Gateway |Media Gateway |Media Gateway
|Control Protocol |Control Protocol |Control Protocol |Control Protocol
| | | |
+------------+ (ATM Network) +------------+ +------------+ (ATM Network) +------------+
|Originating |------------------|Terminating | |Originating |------------------|Terminating |
skipping to change at line 3544 skipping to change at line 3757
It provides the TMGC with the NSAP address and the eecid provided It provides the TMGC with the NSAP address and the eecid provided
by the OMG. by the OMG.
(4) The TMGC sends the appropriate control message to the TMG. This (4) The TMGC sends the appropriate control message to the TMG. This
includes the session descriptor received from the OMG. This includes the session descriptor received from the OMG. This
descriptor contains the NSAP address of the OMG and the EECID descriptor contains the NSAP address of the OMG and the EECID
assigned by the OMG. Additionally, the TMGC instructs the TMG assigned by the OMG. Additionally, the TMGC instructs the TMG
to set up an SVC to the OMG. It also requests the TMG to notify to set up an SVC to the OMG. It also requests the TMG to notify
the TMGC when SVC set-up is complete. Depending on the control the TMGC when SVC set-up is complete. Depending on the control
Rajesh Kumar, Mohamed Mostafa. 69 Rajesh Kumar, Mohamed Mostafa. 73
protocol used, this can be done through a variety of means. protocol used, this can be done through a variety of means.
In the Megaco context, the request to set-up an SVC (not the In the Megaco context, the request to set-up an SVC (not the
notification request for the SVC set-up event) can be made through notification request for the SVC set-up event) can be made through
the following local descriptor: the following local descriptor:
v=0 v=0
o=- 2873397497 0 ATM - - o=- 2873397497 0 ATM - -
s=- s=-
c=ATM - - c=ATM - -
t=0 0 t=0 0
skipping to change at line 3592 skipping to change at line 3805
service-level control message received before from the OMGC. service-level control message received before from the OMGC.
(8) The OMG returns an SVC connect message to the TMG. On receiving (8) The OMG returns an SVC connect message to the TMG. On receiving
this message, the TMG sends an event notification to the TMGC this message, the TMG sends an event notification to the TMGC
indicating successful SVC set-up. indicating successful SVC set-up.
Note that, for this example, the "v=", "o=", "s=" and "t=" lines can be Note that, for this example, the "v=", "o=", "s=" and "t=" lines can be
omitted in the Megaco context. omitted in the Megaco context.
Example use of the Forward Bearer Connection Set-up Model: Example use of the Forward Bearer Connection Set-up Model:
(1) The originating media gateway controller (OMGC) initiates service-level (1) The originating media gateway controller (OMGC) initiates service-level
call establishment by sending the appropriate control message to the call establishment by sending the appropriate control message to the
originating media gateway (OMG). originating media gateway (OMG).
(2) The originating media gateway (OMG) provides its NSAP address Rajesh Kumar, Mohamed Mostafa. 74
Rajesh Kumar, Mohamed Mostafa. 70 (2) The originating media gateway (OMG) provides its NSAP address
to the OMGC, using the following SDP description: to the OMGC, using the following SDP description:
v=0 v=0
o=- 2873397496 0 ATM NSAP o=- 2873397496 0 ATM NSAP
47.0091.8100.0000.0060.3E64.FD01.0060.3E64.FD01.00 47.0091.8100.0000.0060.3E64.FD01.0060.3E64.FD01.00
s=- s=-
c=ATM NSAP c=ATM NSAP
47.0091.8100.0000.0060.3E64.FD01.0060.3E64.FD01.00 47.0091.8100.0000.0060.3E64.FD01.0060.3E64.FD01.00
t=0 0 t=0 0
m=audio $ AAL2/ITU 8 m=audio $ AAL2/ITU 8
skipping to change at line 3649 skipping to change at line 3863
the appropriate mechanism (ISUP with Q.1901 extensions, SIP etc.). the appropriate mechanism (ISUP with Q.1901 extensions, SIP etc.).
It provides the OMGC with the NSAP address and the eecid provided It provides the OMGC with the NSAP address and the eecid provided
by the TMG. by the TMG.
(7) The OMGC sends the appropriate control message to the OMG. This (7) The OMGC sends the appropriate control message to the OMG. This
includes the session descriptor received from the TMG. This includes the session descriptor received from the TMG. This
descriptor contains the NSAP address of the TMG and the EECID descriptor contains the NSAP address of the TMG and the EECID
assigned by the TMG. Additionally, the OMGC instructs the OMG assigned by the TMG. Additionally, the OMGC instructs the OMG
to set up an SVC to the TMG. It also requests the OMG to notify to set up an SVC to the TMG. It also requests the OMG to notify
the OMGC when SVC set-up is complete. Depending on the control the OMGC when SVC set-up is complete. Depending on the control
protocol used, this can be done through a variety of means.
Rajesh Kumar, Mohamed Mostafa. 71 Rajesh Kumar, Mohamed Mostafa. 75
protocol used, this can be done through a variety of means.
In the Megaco context, the request to set-up an SVC (not the In the Megaco context, the request to set-up an SVC (not the
notification request for the SVC set-up event) can be made through notification request for the SVC set-up event) can be made through
the following local descriptor: the following local descriptor:
v=0 v=0
o=- 2873397874 0 ATM - - o=- 2873397874 0 ATM - -
s=- s=-
c=ATM - - c=ATM - -
t=0 0 t=0 0
m=audio $ - - m=audio $ - -
skipping to change at line 3684 skipping to change at line 3898
(10)The TMG uses the eecid to correlate the SVC set-up request with the (10)The TMG uses the eecid to correlate the SVC set-up request with the
service-level control message received before from the TMGC. service-level control message received before from the TMGC.
(11)The TMG returns an SVC connect message to the OMG. On receiving (11)The TMG returns an SVC connect message to the OMG. On receiving
this message, the OMG sends an event notification to the OMGC this message, the OMG sends an event notification to the OMGC
indicating successful SVC set-up. indicating successful SVC set-up.
Note that, for this example, the "v=", "o=", "s=" and "t=" lines can be Note that, for this example, the "v=", "o=", "s=" and "t=" lines can be
omitted in the Megaco context. omitted in the Megaco context.
Rajesh Kumar, Mohamed Mostafa. 72 Rajesh Kumar, Mohamed Mostafa. 76
6.0 List of Parameters with Representations 6.0 List of Parameters with Representations
This section provides a list of the parameters used in this document, This section provides a list of the parameters used in this document,
and the formats used to represent them in SDP descriptions. In general, a and the formats used to represent them in SDP descriptions. In general, a
"-" value can be used for any field that is not specified, is inapplicable "-" value can be used for any field that is not specified, is inapplicable
or is implied. or is implied.
PARAMETER MEANING REPRESENTATION PARAMETER MEANING REPRESENTATION
skipping to change at line 3737 skipping to change at line 3951
representation representation
of <vcci> of <vcci>
<bcg> Bearer Connection Decimal or hex equivalent <bcg> Bearer Connection Decimal or hex equivalent
Group of 8 bits Group of 8 bits
<ex_bcg> Explicit "BCG-" prefixed to <bcg> <ex_bcg> Explicit "BCG-" prefixed to <bcg>
representation representation
of <bcg> of <bcg>
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<portId> Port ID Hex number of up to 32 digits <portId> Port ID Hex number of up to 32 digits
<ex_portId> Explicit "PORT-" prefixed to <portId> <ex_portId> Explicit "PORT-" prefixed to <portId>
representation representation
of <portId> of <portId>
<vpi> Virtual Path Decimal or hex equivalent <vpi> Virtual Path Decimal or hex equivalent
Identifier of 8 or 12 bits Identifier of 8 or 12 bits
skipping to change at line 3786 skipping to change at line 4000
<transport> Transport Values listed in <transport> Transport Values listed in
Table 1. Table 1.
<profile> Profile Decimal integer 1-255 <profile> Profile Decimal integer 1-255
<eecid> End-to-end Up to 8 hex digits <eecid> End-to-end Up to 8 hex digits
Connection Connection
Identifier Identifier
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<aalType> AAL type String values: <aalType> AAL type String values:
"AAL1","AAL1_SDT","AAL1_UDT", "AAL1","AAL1_SDT","AAL1_UDT",
"AAL2", "AAL3/4", "AAL2", "AAL3/4",
"AAL5", "USER_DEFINED_AAL" "AAL5", "USER_DEFINED_AAL"
<asc> ATM service String values: <asc> ATM service String values:
category defined "CBR", "nrt-VBR", "rt-VBR", category defined "CBR", "nrt-VBR", "rt-VBR",
by the ATMF "UBR", "ABR", "GFR" by the ATMF "UBR", "ABR", "GFR"
skipping to change at line 3820 skipping to change at line 4034
<eetim> End-to-end timing String values: "on", <eetim> End-to-end timing String values: "on",
required "off". required "off".
<stc> Susceptibility Decimal equivalent of <stc> Susceptibility Decimal equivalent of
to clipping a 2-bit field to clipping a 2-bit field
<upcc> User plane Decimal equivalent of <upcc> User plane Decimal equivalent of
connection a 2-bit field connection a 2-bit field
configuration configuration
<directionFlag> Direction Flag String values: "f", "b",
"fb"
<cdvType> CDV type String values: <cdvType> CDV type String values:
"PP", "2P" "PP", "2P"
<acdv> Acceptable CDV Decimal equivalent <acdv> Acceptable CDV Decimal equivalent
of 24-bit field of 24-bit field
<ccdv> Cumulative CDV Decimal equivalent <ccdv> Cumulative CDV Decimal equivalent
of 24-bit field of 24-bit field
<eetd> End-to-end transit Decimal equivalent <eetd> End-to-end transit Decimal equivalent
delay of 16-bit field delay of 16-bit field
<cmtd> Cumulative transit Decimal equivalent <cmtd> Cumulative transit Decimal equivalent
delay of 16-bit field delay of 16-bit field
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<aclr> Acceptable Decimal equivalent <aclr> Acceptable Decimal equivalent
Cell Loss Ratio of 8-bit field Cell Loss Ratio of 8-bit field
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<clpLvl> CLP level String values: <clpLvl> CLP level String values:
"0", "0+1" "0", "0+1"
<pcr> Peak Decimal <pcr> Peak Decimal
Cell Rate equivalent of a 24-bit field. Cell Rate equivalent of a 24-bit field.
<scr> Sustained Decimal <scr> Sustained Decimal
Cell Rate equivalent of a 24-bit field Cell Rate equivalent of a 24-bit field
<mbs> Maximum Decimal <mbs> Maximum Decimal
skipping to change at line 3889 skipping to change at line 4106
<bicr> Backward Initial Decimal equivalent of <bicr> Backward Initial Decimal equivalent of
Cell Rate 24-bit field Cell Rate 24-bit field
<ftbe> Forward Transient Decimal equivalent of <ftbe> Forward Transient Decimal equivalent of
Buffer Exposure 24-bit field Buffer Exposure 24-bit field
<btbe> Backward Transient Decimal equivalent of <btbe> Backward Transient Decimal equivalent of
Buffer Exposure 24-bit field Buffer Exposure 24-bit field
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<crmrtt> Cumulative RM Decimal equivalent of <crmrtt> Cumulative RM Decimal equivalent of
round-trip time 24-bit field round-trip time 24-bit field
(Microseconds) (Microseconds)
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<frif> Forward rate Decimal integer <frif> Forward rate Decimal integer
increase factor 0 -15 increase factor 0 -15
<brif> Backward rate Decimal integer <brif> Backward rate Decimal integer
increase factor 0 -15 increase factor 0 -15
<frdf> Forward rate Decimal integer <frdf> Forward rate Decimal integer
decrease factor 0 -15 decrease factor 0 -15
<brdf> Backward rate Decimal integer <brdf> Backward rate Decimal integer
skipping to change at line 3942 skipping to change at line 4159
<cacheTimer> Timer for cached SVC Decimal or hex equivalent <cacheTimer> Timer for cached SVC Decimal or hex equivalent
deletion of 32-bit field deletion of 32-bit field
<bearerSigIEType> Bearer Signaling IE Type 2 hex digits <bearerSigIEType> Bearer Signaling IE Type 2 hex digits
<bearerSigIELng> Bearer Signaling IE Length 1-4 hex digits <bearerSigIELng> Bearer Signaling IE Length 1-4 hex digits
<bearerSigIEVal> Bearer Signaling IE Value Even number of hex digits, <bearerSigIEVal> Bearer Signaling IE Value Even number of hex digits,
2-512 2-512
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<appClass> Application String values: <appClass> Application String values:
specification "itu_h323c","af83", specification "itu_h323c","af83",
"AAL5_SSCOP", "AAL5_SSCOP",
"itu_i3661_unassured", "itu_i3661_unassured",
"itu_i3661_assured", "itu_i3661_assured",
"itu_i3662", "itu_i3662",
"itu_i3651", "itu_i3652", "itu_i3651", "itu_i3652",
"itu_i3653", "itu_i3654", "itu_i3653", "itu_i3654",
"FRF5", "FRF8","FRF11", "FRF5", "FRF8","FRF11",
skipping to change at line 3993 skipping to change at line 4210
<cpcs> Maximum AAL5: Decimal or hex <cpcs> Maximum AAL5: Decimal or hex
CPCS SDU size equivalent of 16 bits CPCS SDU size equivalent of 16 bits
AAL2: 45 or 64, decimal AAL2: 45 or 64, decimal
or hex representation or hex representation
<cidLowerLimit> CID lower limit Decimal integer 8-255 <cidLowerLimit> CID lower limit Decimal integer 8-255
or hex equivalent or hex equivalent
<cidUpperLimit> CID upper limit Decimal integer 8-255 <cidUpperLimit> CID upper limit Decimal integer 8-255
or hex equivalent
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or hex equivalent
<timerCU> Timer, combined use Integer decimal; range <timerCU> Timer, combined use Integer decimal; range
(microseconds) determined by application. (microseconds) determined by application.
Use decimal equivalent of Use decimal equivalent of
32 bits. 32 bits.
<simplifiedCPS> Simplified CPS [52] String values: <simplifiedCPS> Simplified CPS [52] String values:
"on", "off" "on", "off"
<fSDUrate> Forward SDU rate Decimal equivalent of <fSDUrate> Forward SDU rate Decimal equivalent of
skipping to change at line 4046 skipping to change at line 4263
field size, forward or hex equivalent field size, forward or hex equivalent
direction direction
<bsscopuu> Maximum SSCOP-UU Decimal 1- 65524 <bsscopuu> Maximum SSCOP-UU Decimal 1- 65524
field size, backward or hex equivalent field size, backward or hex equivalent
direction direction
<sap> Service Access String values: <sap> Service Access String values:
Point "AUDIO", "MULTIRATE" Point "AUDIO", "MULTIRATE"
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<circuitMode> Circuit Mode String values: <circuitMode> Circuit Mode String values:
Enable "on", "off" Enable "on", "off"
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<frameMode> Frame Mode String values: <frameMode> Frame Mode String values:
Enable "on", "off" Enable "on", "off"
<faxDemod> Fax Demodulation String values: <faxDemod> Fax Demodulation String values:
Enable "on", "off" Enable "on", "off"
<cas> Enable CAS transport String values: <cas> Enable CAS transport String values:
via Type 3 packets "on", "off" via Type 3 packets "on", "off"
<dtmf> Enable DTMF transport String values: <dtmf> Enable DTMF transport String values:
skipping to change at line 4097 skipping to change at line 4314
<silenceTimer> Kick-in timer Decimal or hex representation <silenceTimer> Kick-in timer Decimal or hex representation
for silence of 16-bit field for silence of 16-bit field
suppression suppression
<suppPref> Preferred Silence String values: <suppPref> Preferred Silence String values:
Suppression Method "standard", "custom" Suppression Method "standard", "custom"
<sidUse> SID Use String values: <sidUse> SID Use String values:
Method "No SID", "Fixed Noise", Method "No SID", "Fixed Noise",
"Sampled Noise"
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"Sampled Noise"
<fxnslevel> Fixed Noise Decimal or hex representation <fxnslevel> Fixed Noise Decimal or hex representation
Level of a 7-bit field Level of a 7-bit field
<ecanEnable> Enable Echo String values: <ecanEnable> Enable Echo String values:
Cancellation "on", "off" Cancellation "on", "off"
<ecanType> Type of Echo String values: <ecanType> Type of Echo String values:
Cancellation "G165", "G168" Cancellation "G165", "G168"
skipping to change at line 4134 skipping to change at line 4351
any value from column 2 any value from column 2
of Table 2 of Table 2
<packetLength> Packet length Decimal integer 0-45 <packetLength> Packet length Decimal integer 0-45
<packetTime> Packetization Decimal integer 1-65,536 <packetTime> Packetization Decimal integer 1-65,536
Interval in microsec. Interval in microsec.
<fxIncl> Facsimile included String values: "on", "off" <fxIncl> Facsimile included String values: "on", "off"
<serviceType> Service type String values: "v", "d", "f",
"df", "all"
<q7655scc> Contents of the Even number of hex <q7655scc> Contents of the Even number of hex
Q.765.5 Single digits (4-32) Q.765.5 Single digits (4-32)
Codec IE Codec IE
<isupUsi> ISUP User Service Two hex digits <isupUsi> ISUP User Service Even number of hex digits
Information Information (4-24)
<uiLayer1Prot> User Information Two hex digits
Layer 1 Protocol
<chainPointer> Chain pointer String values: "NEXT", <chainPointer> Chain pointer String values: "NEXT",
"PREVIOUS", "NULL" "PREVIOUS", "NULL"
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<rtcpPortNum> RTCP port number for Odd decimal in range 1,024 to <rtcpPortNum> RTCP port number for Odd decimal in range 1,024 to
H.323 Annex C 65,535. H.323 Annex C 65,535.
applications Preferred: Odd number in applications Preferred: Odd number in
the range 49,152 to 65,535 the range 49,152 to 65,535
<rtcpIPaddr> IP address for receipt Dotted decimal, 7-15 chars <rtcpIPaddr> IP address for receipt Dotted decimal, 7-15 chars
of RTCP packets of RTCP packets
Rajesh Kumar, Mohamed Mostafa. 81
7.0 Examples of ATM session descriptions using SDP 7.0 Examples of ATM session descriptions using SDP
An example of a complete AAL1 session description in SDP is: An example of a complete AAL1 session description in SDP is:
v=0 v=0
o=- A3C47F21456789F0 0 ATM NSAP o=- A3C47F21456789F0 0 ATM NSAP
47.0091.8100.0000.0060.3e64.fd01.0060.3e64.fd01.00 47.0091.8100.0000.0060.3e64.fd01.0060.3e64.fd01.00
s=- s=-
c=ATM NSAP c=ATM NSAP
47.0091.8100.0000.0060.3e64.fd01.0060.3e64.fd01.00 47.0091.8100.0000.0060.3e64.fd01.0060.3e64.fd01.00
skipping to change at line 4198 skipping to change at line 4421
o=- A3C47F21456789F0 0 ATM NSAP o=- A3C47F21456789F0 0 ATM NSAP
47.0091.8100.0000.0060.3e64.fd01.0060.3e64.fd01.00 47.0091.8100.0000.0060.3e64.fd01.0060.3e64.fd01.00
s=- s=-
c=ATM NSAP c=ATM NSAP
47.0091.8100.0000.0060.3e64.fd01.0060.3e64.fd01.00 47.0091.8100.0000.0060.3e64.fd01.0060.3e64.fd01.00
t=0 0 t=0 0
m=audio $ AAL2/ITU 8 AAL2/custom 100 AAL2/ITU 1 m=audio $ AAL2/ITU 8 AAL2/custom 100 AAL2/ITU 1
a=eecid:B3E32 a=eecid:B3E32
a=profileDesc:AAL2/custom 100 0-7 PCMG 40 5000 0-7 SIDG 1 a=profileDesc:AAL2/custom 100 0-7 PCMG 40 5000 0-7 SIDG 1
5000 8-15 G726-32 40 10000 8-15 SIDG 1 5000 5000 8-15 G726-32 40 10000 8-15 SIDG 1 5000
Rajesh Kumar, Mohamed Mostafa. 86
a=vsel:G726-32 40 10000 a=vsel:G726-32 40 10000
a=dsel:off PCMU - - a=dsel:off PCMU - -
a=fsel:G726-32 40 10000 a=fsel:G726-32 40 10000An example of an SDP session descriptor for an AAL5
switched virtual circuit
Rajesh Kumar, Mohamed Mostafa. 82
An example of an SDP session descriptor for an AAL5 switched virtual circuit
for delivering MPEG-2 video: for delivering MPEG-2 video:
v=0 v=0
o=- A3C47F21456789F0 0 ATM NSAP o=- A3C47F21456789F0 0 ATM NSAP
47.0091.8100.0000.0060.3e64.fd01.0060.3e64.fd01.00 47.0091.8100.0000.0060.3e64.fd01.0060.3e64.fd01.00
s=- s=-
c=ATM NSAP 47.0091.8100.0000.0060.3e64.fd01.0060.3e64.fd01.00 c=ATM NSAP 47.0091.8100.0000.0060.3e64.fd01.0060.3e64.fd01.00
t=0 0 t=0 0
m=video $ AAL5/ITU 33 m=video $ AAL5/ITU 33
a=eecid:B3E32 a=eecid:B3E32
a=aalType:AAL5 a=aalType:AAL5
a=bearerType:SVC on a=bearerType:SVC on
a=atmFtrfcDesc:0+1 7816 - - - - - off - a=atmTrfcDesc:f 0+1 7816 - - - - - off -
a=atmBtrfcDesc:0+1 0 - - - - - on - a=atmTrfcDesc:b 0+1 0 - - - - - on -
a=fcpsSDUsize:20680 a=cpsSDUsize:f 20680
a=aalApp:itu_h2221 - - a=aalApp:itu_h2221 - -
An example of an SDP session descriptor for an AAL5 permanent virtual circuit An example of an SDP session descriptor for an AAL5 permanent virtual circuit
for delivering MPEG-2 video: for delivering MPEG-2 video:
v=0 v=0
o=- A3C47F21456789F0 0 ATM - - o=- A3C47F21456789F0 0 ATM - -
s=- s=-
c=ATM - - c=ATM - -
t=0 0 t=0 0
m=video PORT-$/VPI-0/VCI-$ AAL5/ITU 33 m=video PORT-$/VPI-0/VCI-$ AAL5/ITU 33
a=bearerType:PVC - a=bearerType:PVC -
a=atmFtrfcDesc:0+1 7816 - - - - - off - a=atmTrfcDesc:f 0+1 7816 - - - - - off -
a=atmBtrfcDesc:0+1 0 - - - - - on - a=atmTrfcDesc:b 0+1 0 - - - - - on -
a=fcpsSDUsize:20680 a=cpsSDUsize:f 20680
a=aalApp:itu_h2221 - - a=aalApp:itu_h2221 - -
8.0 Security Considerations 8.0 Security Considerations
8.1 Bearer Security 8.1 Bearer Security
At present, standard means of encrypting ATM and AAL2 bearers At present, standard means of encrypting ATM and AAL2 bearers
are not conventionalized in the same manner as means of encrypting RTP are not conventionalized in the same manner as means of encrypting RTP
payloads. Nor has the authentication of ATM or AAL2 bearer payloads. Nor has the authentication of ATM or AAL2 bearer
signaling. signaling.
The SDP encryption key line (k=) defined in rfc2327 can be used The SDP encryption key line (k=) defined in rfc2327 can be used
to represent the encryption key and the method of obtaining the to represent the encryption key and the method of obtaining the
key. In the ATM and AAL2 contexts, the term 'bearer' can include key. In the ATM and AAL2 contexts, the term 'bearer' can include
'bearer signaling' as well as 'bearer payloads'. 'bearer signaling' as well as 'bearer payloads'.
Rajesh Kumar, Mohamed Mostafa. 87
8.2 Security of the SDP description 8.2 Security of the SDP description
The SDP session descriptions might originate in untrusted areas The SDP session descriptions might originate in untrusted areas
such as equipment owned by end-subscribers or located at end-subscriber such as equipment owned by end-subscribers or located at end-subscriber
Rajesh Kumar, Mohamed Mostafa. 83
premises. SDP relies on the security mechanisms of the encapsulating premises. SDP relies on the security mechanisms of the encapsulating
protocol or layers below the encapsulating protocol. Examples of protocol or layers below the encapsulating protocol. Examples of
encapsulating protocols are the Session Initiation Protocol (SIP), encapsulating protocols are the Session Initiation Protocol (SIP),
MGCP and Multimedia Gateway Control Protocol (MEGACO). No additional MGCP and Multimedia Gateway Control Protocol (MEGACO). No additional
security mechanisms are needed. SIP, MGCP and MEGACO security mechanisms are needed. SIP, MGCP and MEGACO
can use IPSec authentication as described in RFC1826 [Ref. can use IPSec authentication as described in RFC1826 [Ref.
27]. IPSec encryption can be optionally used with authentication to 27]. IPSec encryption can be optionally used with authentication to
provide an additional, potentially more expensive level of security. provide an additional, potentially more expensive level of security.
IPSec security associations can be made between equipment located in IPSec security associations can be made between equipment located in
untrusted areas and equipment located in trusted areas through untrusted areas and equipment located in trusted areas through
skipping to change at line 4305 skipping to change at line 4527
EOL = (CR / LF / CRLF) ; as per Megaco RFC EOL = (CR / LF / CRLF) ; as per Megaco RFC
CR = %d13 CR = %d13
LF = %d10 LF = %d10
decimal-uchar = DIGIT decimal-uchar = DIGIT
/ POS-DIGIT DIGIT / POS-DIGIT DIGIT
/ ("1" 2*(DIGIT)) / ("1" 2*(DIGIT))
/ ("2" ("0"/"1"/"2"/"3"/"4") DIGIT) / ("2" ("0"/"1"/"2"/"3"/"4") DIGIT)
/ ("2" "5" ("0"/"1"/"2"/"3"/"4"/"5")) / ("2" "5" ("0"/"1"/"2"/"3"/"4"/"5"))
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generic-U8 = (hex-prefix hex-U8) / decimal-uchar generic-U8 = (hex-prefix hex-U8) / decimal-uchar
generic-U12 = (hex-prefix hex-U12) / 1*4 (DIGIT) generic-U12 = (hex-prefix hex-U12) / 1*4 (DIGIT)
generic-U16 = (hex-prefix hex-U16) / 1*5(DIGIT) generic-U16 = (hex-prefix hex-U16) / 1*5(DIGIT)
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generic-U24 = (hex-prefix hex-U24) / 1*8(DIGIT) generic-U24 = (hex-prefix hex-U24) / 1*8(DIGIT)
generic-U32 = (hex-prefix hex-U32) / 1*10(DIGIT) generic-U32 = (hex-prefix hex-U32) / 1*10(DIGIT)
hex-U8 = 1*2(HEXDIG) hex-U8 = 1*2(HEXDIG)
hex-U12 = 1*3(HEXDIG) hex-U12 = 1*3(HEXDIG)
hex-U16 = 1*4(HEXDIG) hex-U16 = 1*4(HEXDIG)
hex-U24 = 1*6(HEXDIG) hex-U24 = 1*6(HEXDIG)
hex-U32 = 1*8(HEXDIG) hex-U32 = 1*8(HEXDIG)
generic-U8-or-null = generic-U8 / "-" generic-U8-or-null = generic-U8 / "-"
generic-U12-or-null = generic-U12 / "-" generic-U12-or-null = generic-U12 / "-"
generic-U16-or-null = generic-U16 / "-" generic-U16-or-null = generic-U16 / "-"
skipping to change at line 4357 skipping to change at line 4578
net-type-addr= nettype space addrtype-addr net-type-addr= nettype space addrtype-addr
netttype = "ATM" / "IN" / "TN" / "-" / "$" netttype = "ATM" / "IN" / "TN" / "-" / "$"
; Other nettype values may be defined in the future in other documents ; Other nettype values may be defined in the future in other documents
; Validity of nettype and addrtype-addr combination to be checked at ; Validity of nettype and addrtype-addr combination to be checked at
; application level, not protocol syntax level ; application level, not protocol syntax level
addrtype-addr = atm-addrtype-addr / ip-addrtype-addr / tn-addrtype-addr addrtype-addr = atm-addrtype-addr / ip-addrtype-addr / tn-addrtype-addr
; ip-addrtype-addr per rfc2327 ; ip-addrtype-addr per rfc2327
; tn-addrtype-addr per rfc2848
Rajesh Kumar, Mohamed Mostafa. 85 Rajesh Kumar, Mohamed Mostafa. 89
; tn-addrtype-addr per rfc2848
; ATM address definition ; ATM address definition
atm-addrtype-addr = atm-nsap-addr / atm-e164-addr / atm-alias-addr atm-addrtype-addr = atm-nsap-addr / atm-e164-addr / atm-alias-addr
atm-nsap-addr = ("NSAP" / "-" / "$") space (nsap-addr / "-" / "$") atm-nsap-addr = ("NSAP" / "-" / "$") space (nsap-addr / "-" / "$")
atm-e164-addr = ("E164" / "-" / "$") space (e164-addr / "-" / "$") atm-e164-addr = ("E164" / "-" / "$") space (e164-addr / "-" / "$")
atm-alias-addr = ("GWID" / "ALIAS" / "-" / "$") space (alias-addr / "-" / "$") atm-alias-addr = ("GWID" / "ALIAS" / "-" / "$") space (alias-addr / "-" / "$")
nsap-addr = 2(HEXDIG) "." 9(4(HEXDIG) ".") 2(HEXDIG) nsap-addr = 2(HEXDIG) "." 9(4(HEXDIG) ".") 2(HEXDIG)
skipping to change at line 4408 skipping to change at line 4629
bandwidth = 1*(DIGIT) bandwidth = 1*(DIGIT)
time-fields = *( "t=" start-time space stop-time *(EOL repeat-fields) EOL) time-fields = *( "t=" start-time space stop-time *(EOL repeat-fields) EOL)
[zone-adjustments EOL] [zone-adjustments EOL]
start-time = time / "0" start-time = time / "0"
stop-time = time / "0" ; always "0" in ATM stop-time = time / "0" ; always "0" in ATM
time = POS-DIGIT 9*(DIGIT) ; same as rfc2327 time = POS-DIGIT 9*(DIGIT) ; same as rfc2327
; repeat-fields and zone-adjustments per rfc2327, not used in ATM ; repeat-fields and zone-adjustments per rfc2327, not used in ATM
; Definition of optional key-field per rfc2327 ; Definition of optional key-field per rfc2327
Rajesh Kumar, Mohamed Mostafa. 90
; ;
attribute-fields = *("a=" attribute EOL) attribute-fields = *("a=" attribute EOL)
Rajesh Kumar, Mohamed Mostafa. 86
; SDP descriptors for ATM do not have session-level media attribute lines ; SDP descriptors for ATM do not have session-level media attribute lines
; If these are provided, they should be ignored. ; If these are provided, they should be ignored.
media-descriptions = *(media-description) media-descriptions = *(media-description)
media-description = media-field information-field *(connection-field) media-description = media-field information-field *(connection-field)
bandwidth-fields key-field attribute-fields bandwidth-fields key-field attribute-fields
; Definitions of information-field per rfc2327. This fields are omitted in ; Definitions of information-field per rfc2327. This fields are omitted in
; ATM SDP descriptions. If received, they are ignored in the ATM context ; ATM SDP descriptions. If received, they are ignored in the ATM context
; ;
skipping to change at line 4461 skipping to change at line 4683
(atm-type-addr-m "/" ex-vpci "/" ex-vci) / (atm-type-addr-m "/" ex-vpci "/" ex-vci) /
(atm-type-addr-m "/" ex-vpci "/" ex-vci "/" ex-cid) (atm-type-addr-m "/" ex-vpci "/" ex-vci "/" ex-cid)
atm-type-addr-m = atm-nsap-addr-m / atm-e164-addr-m / atm-alias-addr-m atm-type-addr-m = atm-nsap-addr-m / atm-e164-addr-m / atm-alias-addr-m
atm-nsap-addr-m = ["NSAP-"] (nsap-addr / "$") atm-nsap-addr-m = ["NSAP-"] (nsap-addr / "$")
atm-e164-addr-m = ["E164-"] (e164-addr / "$") atm-e164-addr-m = ["E164-"] (e164-addr / "$")
atm-alias-addr-m = ["GWID-" / "ALIAS-"] (alias-addr / "$") atm-alias-addr-m = ["GWID-" / "ALIAS-"] (alias-addr / "$")
; The -m at the end indicates use in the media field ; The -m at the end indicates use in the media field
; Wildcarding rules different from ATM address on 'o' and 'c' lines ; Wildcarding rules different from ATM address on 'o' and 'c' lines
Rajesh Kumar, Mohamed Mostafa. 91
ex-vcci = "VCCI-" vcci ex-vcci = "VCCI-" vcci
ex-cid = "CID-" cid ex-cid = "CID-" cid
ex-bcg = "BCG-" bcg ex-bcg = "BCG-" bcg
Rajesh Kumar, Mohamed Mostafa. 87
ex-portid = "PORT-" portid ex-portid = "PORT-" portid
ex-vpi = "VPI-" vpi ex-vpi = "VPI-" vpi
ex-vci = "VCI-" vci ex-vci = "VCI-" vci
ex-vpci = "VPCI-" vpci ex-vpci = "VPCI-" vpci
vcci = generic-U16 vcci = generic-U16
cid = generic-U8 cid = generic-U8
bcg = generic-U8 bcg = generic-U8
portid = 1*32 (HEXDIG) portid = 1*32 (HEXDIG)
vpi = generic-U12 vpi = generic-U12
skipping to change at line 4514 skipping to change at line 4735
rtp-transport = "RTP" "/" rtp-transport-list rtp-transport = "RTP" "/" rtp-transport-list
rtp-transport-list = "AVP" rtp-transport-list = "AVP"
aal1-fmt-list = (payload-type *(space payload-type)) / "-" aal1-fmt-list = (payload-type *(space payload-type)) / "-"
payload-type = decimal-uchar payload-type = decimal-uchar
aal5-fmt-list = aal1-fmt-list aal5-fmt-list = aal1-fmt-list
rtp-fmt-list = aal1-fmt-list rtp-fmt-list = aal1-fmt-list
aal2-fmt-list = (profile *(space profile)) / "-" aal2-fmt-list = (profile *(space profile)) / "-"
profile = decimal-uchar profile = decimal-uchar
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attribute-fields = *("a=" attribute EOL) attribute-fields = *("a=" attribute EOL)
attribute = known-attribute / (generic-att-field ":" att-value) / attribute = known-attribute / (generic-att-field ":" att-value) /
generic-att-field generic-att-field
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generic-att-field = 1*(alpha-numeric) generic-att-field = 1*(alpha-numeric)
att-value = byte-string att-value = byte-string
known-attribute = atm-attribute / PINT-attribute / rfc2327-attribute known-attribute = atm-attribute / PINT-attribute / rfc2327-attribute
; PINT-attribute as defined in rfc2848 ; PINT-attribute as defined in rfc2848
; rfc2327 attribute as defined in that rfc ; rfc2327 attribute as defined in that rfc
atm-attribute = atm-attribute =
"eecid" ":" eecid / "eecid" ":" eecid /
"aalType" ":" aalType / "aalType" ":" aalType /
"capability" ":" (asc / atc) space subtype / "capability" ":" (asc / atc) space subtype /
"qosclass" ":" qosclass / "qosclass" ":" qosclass /
"bcob" ":" bcob space eetim / "bcob" ":" bcob space eetim /
"stc" ":" stc / "stc" ":" stc /
"upcc" ":" upcc / "upcc" ":" upcc /
"atmQOSfparms" ":" cdvType space acdv space ccdv space eetd space cmtd "atmQOSparms" ":" directionFlag space cdvType
space aclr / space acdv space ccdv space eetd space cmtd space aclr /
"atmQOSbparms" ":" cdvType space acdv space ccdv space eetd space cmtd "atmTrfcDesc" ":" directionFlag space clpLvl
space aclr / space pcr space scr space mbs space cdvt space
"atmFtrfcDesc" ":" clpLvl space pcr space scr space mbs space cdvt space
mcr space mfs space fd space te /
"atmBtrfcDesc" ":" clpLvl space pcr space scr space mbs space cdvt space
mcr space mfs space fd space te / mcr space mfs space fd space te /
"abrFparms" ":" nrm space trm space cdf space adtf / "abrParms" ":" directionFlag space nrm space trm space cdf space adtf /
"abrBparms" ":" nrm space trm space cdf space adtf /
"abrSetup" ":" ficr space bicr space ftbe space btbe space "abrSetup" ":" ficr space bicr space ftbe space btbe space
crmrtt space frif space brif space frdf space brdf / crmrtt space frif space brif space frdf space brdf /
"bearertype" ":" bearerType space localInitiation / "bearertype" ":" bearerType space localInitiation /
"lij" ":" sci space lsn / "lij" ":" sci space lsn /
"anycast" ":" atmGroupAddress space cdStd space "anycast" ":" atmGroupAddress space cdStd space
conScpTyp space conScpSel / conScpTyp space conScpSel /
"cache" ":" cacheEnable space cacheTimer / "cache" ":" cacheEnable space cacheTimer /
"bearerSigIE" ":" bearerSigIEType space "bearerSigIE" ":" bearerSigIEType space
bearerSigIELng space bearerSigIEVal / bearerSigIELng space bearerSigIEVal /
"aalApp" ":" appClass space oui space appId / "aalApp" ":" appClass space oui space appId /
"cbrRate" ":" cbrRate / "cbrRate" ":" cbrRate /
"sbc" ":" sbc / "sbc" ":" sbc /
"clkrec" ":" clkrec / "clkrec" ":" clkrec /
"fec" ":" fecEnable / "fec" ":" fecEnable /
"prtfl" ":" partialFill / "prtfl" ":" partialFill /
"structure" ":" structureEnable space blksz / "structure" ":" structureEnable space blksz /
"fcpsSDUsize" ":" cpcs / "cpsSDUsize" ":" directionFlag space cpcs /
"bcpsSDUsize" ":" cpcs /
"aal2CPS" ":" cidLowerLimit space cidUpperLimit space "aal2CPS" ":" cidLowerLimit space cidUpperLimit space
timerCU space simplifiedCPS / timerCU space simplifiedCPS /
"aal2CPSSDUrate" ":" fSDUrate space bSDUrate / "aal2CPSSDUrate" ":" fSDUrate space bSDUrate /
"aal2sscs3661unassured" ":" ted space rastimer space fsssar "aal2sscs3661unassured" ":" ted space rastimer space fsssar
space bsssar / space bsssar /
"aal2sscs3661assured" ":" rastimer space fsssar space bsssar "aal2sscs3661assured" ":" rastimer space fsssar space bsssar
space fsscopsdu space bsscopsdu space fsscopuu space bsscopuu / space fsscopsdu space bsscopsdu space fsscopuu space bsscopuu /
"aal2sscs3662" ":" sap space circuitMode space frameMode space faxDemod "aal2sscs3662" ":" sap space circuitMode space frameMode space faxDemod
space cas space dtmf space mfall space mfr1 space cas space dtmf space mfall space mfr1
space mfr2 space PCMencoding space fmaxFrame space bmaxFrame / space mfr2 space PCMencoding space fmaxFrame space bmaxFrame /
Rajesh Kumar, Mohamed Mostafa. 89
"aal5sscop" ":" fsscopsdu space bsscopsdu space fsscopuu "aal5sscop" ":" fsscopsdu space bsscopsdu space fsscopuu
Rajesh Kumar, Mohamed Mostafa. 93
space bsscopuu / space bsscopuu /
"atmmap" ":" payload-type space encoding-name / "atmmap" ":" payload-type space encoding-name /
"silenceSupp" ":" silenceSuppEnable space silenceTimer space suppPref "silenceSupp" ":" silenceSuppEnable space silenceTimer space suppPref
space sidUse space fxnslevel / space sidUse space fxnslevel /
"ecanf" ":" ecanEnable space ecanType / "ecan" ":" directionFlag space ecanEnable space ecanType /
"ecanb" ":" ecanEnable space ecanType / "gc" ":" directionFlag space gcEnable space gcLvl /
"gcf" ":" gcEnable space gcLvl /
"gcb" ":" gcEnable space gcLvl /
"profileDesc" ":" aal2-transport space profile space "profileDesc" ":" aal2-transport space profile space
1*(profile-row) / 1*(profile-row) /
"vsel" ":" 1*(encoding-name space packet-length space "vsel" ":" 1*(encoding-name space packet-length space
packet-time space) / packet-time space) /
"dsel" ":" fxIncl space "dsel" ":" fxIncl space
1*(encoding-name space packet-length space 1*(encoding-name space packet-length space
packet-time space) / packet-time space) /
"fsel" ":" 1*(encoding-name space packet-length space "fsel" ":" 1*(encoding-name space packet-length space
packet-time space) / packet-time space) /
"onewaySel" ":" serviceType space directionFlag space
1*(encoding-name space packet-length space
packet-time space) /
"codecconfig" ":" q7655scc / "codecconfig" ":" q7655scc /
"isup_usi" ":" isupUsi / "isup_usi" ":" isupUsi /
"uiLayer1_Prot" ":" uiLayer1Prot /
"chain" ":" chainPointer "chain" ":" chainPointer
eecid = 8 (HEXDIG) eecid = 8 (HEXDIG)
aalType = "AAL1" / "AAL2" / "AAL3/4" / "AAL5" / "USER_DEFINED_AAL" aalType = "AAL1" / "AAL2" / "AAL3/4" / "AAL5" / "USER_DEFINED_AAL"
asc = "CBR" / "nrt-VBR" / "rt-VBR" / "UBR" / "ABR" / "GFR" asc = "CBR" / "nrt-VBR" / "rt-VBR" / "UBR" / "ABR" / "GFR"
atc = "DBR" / "SBR" / "ABT/IT" / "ABT/DT" / "ABR" atc = "DBR" / "SBR" / "ABT/IT" / "ABT/DT" / "ABR"
subtype = decimal-U8-or-null subtype = decimal-U8-or-null
qosclass = decimal-U8-or-null qosclass = decimal-U8-or-null
bcob = generic-U8 bcob = generic-U8
eetim = on-off-or-null eetim = on-off-or-null
stc = decimal-uchar stc = decimal-uchar
upcc = decimal-uchar upcc = decimal-uchar
directionFlag = "f" / "b" / "fb"
cdvType = "PP" / "2P" / "-" cdvType = "PP" / "2P" / "-"
acdv = decimal-U32-or-null acdv = decimal-U32-or-null
ccdv = decimal-U32-or-null ccdv = decimal-U32-or-null
eetd = decimal-U16-or-null eetd = decimal-U16-or-null
cmtd = decimal-U16-or-null cmtd = decimal-U16-or-null
aclr = decimal-U8-or-null aclr = decimal-U8-or-null
clpLvl = "0" / "0+1" / "-" clpLvl = "0" / "0+1" / "-"
pcr = decimal-U24-or-null pcr = decimal-U24-or-null
scr = decimal-U24-or-null scr = decimal-U24-or-null
mbs = decimal-U16-or-null mbs = decimal-U16-or-null
cdvt = decimal-U24-or-null cdvt = decimal-U24-or-null
mcr = decimal-U24-or-null mcr = decimal-U24-or-null
mfs = decimal-U16-or-null mfs = decimal-U16-or-null
fd = on-off-or-null fd = on-off-or-null
te = on-off-or-null te = on-off-or-null
nrm = generic-U8-or-null nrm = generic-U8-or-null
trm = generic-U8-or-null trm = generic-U8-or-null
cdf = generic-U8-or-null
adtf = generic-U16-or-null
Rajesh Kumar, Mohamed Mostafa. 90 Rajesh Kumar, Mohamed Mostafa. 94
cdf = generic-U8-or-null
adtf = generic-U16-or-null
ficr = decimal-U24-or-null ficr = decimal-U24-or-null
bicr = decimal-U24-or-null bicr = decimal-U24-or-null
ftbe = decimal-U24-or-null ftbe = decimal-U24-or-null
btbe = decimal-U24-or-null btbe = decimal-U24-or-null
crmrtt = decimal-U24-or-null crmrtt = decimal-U24-or-null
frif = 1*2 (DIGIT) frif = 1*2 (DIGIT)
brif = 1*2 (DIGIT) brif = 1*2 (DIGIT)
frdf = 1*2 (DIGIT) frdf = 1*2 (DIGIT)
brdf = 1*2 (DIGIT) brdf = 1*2 (DIGIT)
bearerType = "PVC" / "SVC" / "CID" bearerType = "PVC" / "SVC" / "CID"
skipping to change at line 4679 skipping to change at line 4897
simplifiedCPS = on-off-or-null simplifiedCPS = on-off-or-null
fSDUrate = decimal-U24-or-null fSDUrate = decimal-U24-or-null
bSDUrate = decimal-U24-or-null bSDUrate = decimal-U24-or-null
ted = on-off-or-null ted = on-off-or-null
rastimer = decimal-U32-or-null rastimer = decimal-U32-or-null
fsssar = generic-U24-or-null fsssar = generic-U24-or-null
bsssar = generic-U24-or-null bsssar = generic-U24-or-null
fsscopsdu = generic-U16-or-null fsscopsdu = generic-U16-or-null
bsscopsdu = generic-U16-or-null bsscopsdu = generic-U16-or-null
fsscopuu = generic-U16-or-null fsscopuu = generic-U16-or-null
bsscopuu = generic-U16-or-null
sap = "AUDIO" / "MULTIRATE" / "-"
Rajesh Kumar, Mohamed Mostafa. 91 Rajesh Kumar, Mohamed Mostafa. 95
bsscopuu = generic-U16-or-null
sap = "AUDIO" / "MULTIRATE" / "-"
circuitMode = on-off-or-null circuitMode = on-off-or-null
frameMode = on-off-or-null frameMode = on-off-or-null
faxDemod = on-off-or-null faxDemod = on-off-or-null
cas = on-off-or-null cas = on-off-or-null
dtmf = on-off-or-null dtmf = on-off-or-null
mfall = on-off-or-null mfall = on-off-or-null
mfr1 = on-off-or-null mfr1 = on-off-or-null
mfr2 = on-off-or-null mfr2 = on-off-or-null
PCMencoding = "PCMA" / "PCMU" / "-" PCMencoding = "PCMA" / "PCMU" / "-"
fmaxframe = generic-U16-or-null fmaxframe = generic-U16-or-null
skipping to change at line 4720 skipping to change at line 4938
"PCMU" / "G726-32" / "G723" / "PCMA" / "G722" / "G728" / "PCMU" / "G726-32" / "G723" / "PCMA" / "G722" / "G728" /
"G729" / "X-G729a" / "X-G729b" / "X-G729ab" / "X-G726-16" / "G729" / "X-G729a" / "X-G729b" / "X-G729ab" / "X-G726-16" /
"X-G726-24" / "X-G726-40" / "X-G7231-H" / "X-G7231-L" / "X-G726-24" / "X-G726-40" / "X-G7231-H" / "X-G7231-L" /
"X-G7231a-H" / "X-G7231a-L" / "X-G727-16" / "X-G727-24" / "X-G7231a-H" / "X-G7231a-L" / "X-G727-16" / "X-G727-24" /
"X-G727-32" / "X-G727-32" /
"X-CCD" / "X-CCD-CAS" / "GSM" / "GSM-HR" / "GSM-EFR" / "X-CCD" / "X-CCD-CAS" / "GSM" / "GSM-HR" / "GSM-EFR" /
"GSM-EHR" / "X-FXDMOD-3" / "1016" / "DVI4" / "L16" / "LPC" / "GSM-EHR" / "X-FXDMOD-3" / "1016" / "DVI4" / "L16" / "LPC" /
"MPA" / "QCELP" / "H263" / "H263-1998" / "MPA" / "QCELP" / "H263" / "H263-1998" /
"JPEG" / "H261" / "MPV" / "MP2T" / "nv" / "RED" / "JPEG" / "H261" / "MPV" / "MP2T" / "nv" / "RED" /
"CelB" / "L8" / "VDVI" / "MP1S" / "MP2P" / "BT656" / "CelB" / "L8" / "VDVI" / "MP1S" / "MP2P" / "BT656" /
"FR-AMR" / "HR-AMR" / "HR-UMTS" "FR-AMR" / "HR-AMR" / "UMTS-AMR" / "AMR"
packet-length = decimal-U8-or-null packet-length = decimal-U8-or-null
packet-time = decimal-U16-or-null packet-time = decimal-U16-or-null
fxIncl = on-off-or-null fxIncl = on-off-or-null
serviceType = "v" / "d" / "f" / "df" / "all"
q7655scc = 4*32 (HEXDIG) q7655scc = 4*32 (HEXDIG)
isupUsi = 2 (HEXDIG) isupUsi = 4*24 (HEXDIG)
uiLayer1Prot = 2 (HEXDIG)
chainPointer = "NEXT" / "PREVIOUS" / "NULL" chainPointer = "NEXT" / "PREVIOUS" / "NULL"
References References
Rajesh Kumar, Mohamed Mostafa. 96
[1] IETF RFC 2327, 'SDP: Session Description Protocol', April '98, [1] IETF RFC 2327, 'SDP: Session Description Protocol', April '98,
Mark Handley and Van Jacobson. Mark Handley and Van Jacobson.
Rajesh Kumar, Mohamed Mostafa. 92
[2] IETF RFC 1889, 'RTP: A Transport Protocol for Real-Time [2] IETF RFC 1889, 'RTP: A Transport Protocol for Real-Time
Applications', Jan. 1996. Applications', Jan. 1996.
RFC1889 will be obsoleted, in a substantially backwards compatible RFC1889 will be obsoleted, in a substantially backwards compatible
manner, by the RFC that evolves out of draft-ietf-avt-rtp-new-08.txt. manner, by the RFC that evolves out of draft-ietf-avt-rtp-new-08.txt.
[3] IETF RFC 1890, 'RTP Profile for Audio and Video Conferences [3] IETF RFC 1890, 'RTP Profile for Audio and Video Conferences
with Minimal Control', Jan. 1996. with Minimal Control', Jan. 1996.
RFC1890 will be obsoleted, in a fully backwards compatible manner, RFC1890 will be obsoleted, in a fully backwards compatible manner,
skipping to change at line 4784 skipping to change at line 5004
Convergence Sublayer for AAL Type 2, June 1998. Convergence Sublayer for AAL Type 2, June 1998.
[13] ITU-T I.366.2, AAL Type 2 Reassembly Service Specific [13] ITU-T I.366.2, AAL Type 2 Reassembly Service Specific
Convergence Sublayer for Trunking, Feb. 99. Convergence Sublayer for Trunking, Feb. 99.
[14] Draft ietf-avt-telephone-tones-05.txt, RTP payloads for [14] Draft ietf-avt-telephone-tones-05.txt, RTP payloads for
Telephone Signal Events, S.B.Petrack, Nov. 17, 1998. Telephone Signal Events, S.B.Petrack, Nov. 17, 1998.
[15] ITU-T Q.2931, B-ISDN Application Protocol for Access Signaling. [15] ITU-T Q.2931, B-ISDN Application Protocol for Access Signaling.
Rajesh Kumar, Mohamed Mostafa. 97
[16] Amendment 1, 2, 3 and 4 to ITU-T Q.2931, B-ISDN Application [16] Amendment 1, 2, 3 and 4 to ITU-T Q.2931, B-ISDN Application
Protocol for Access Signaling. Protocol for Access Signaling.
Rajesh Kumar, Mohamed Mostafa. 93
[17] SAP: Session Announcement Protocol , draft-ietf-mmusic-sap-v2- [17] SAP: Session Announcement Protocol , draft-ietf-mmusic-sap-v2-
04.txt, Mark Handley, Colin Perkins and Edmund Whelan . 04.txt, Mark Handley, Colin Perkins and Edmund Whelan .
[18] rfc2543, Handley, M., H. Schulzrinne , Schooler, E. and [18] rfc2543, Handley, M., H. Schulzrinne , Schooler, E. and
Rosenberg, J., "Session Initiation Protocol (SIP)", March Rosenberg, J., "Session Initiation Protocol (SIP)", March
1999. 1999.
[19] rfc1349, Type of Service in the Internet Protocol Suite. P. [19] rfc1349, Type of Service in the Internet Protocol Suite. P.
Almquist. July 1992. Almquist. July 1992.
skipping to change at line 4837 skipping to change at line 5057
[30] ATM Forum Addressing: Reference Guide, af-ra-0106.000. [30] ATM Forum Addressing: Reference Guide, af-ra-0106.000.
[31] http://www.isi.edu/in-notes/iana/assignments/rtp-parameters [31] http://www.isi.edu/in-notes/iana/assignments/rtp-parameters
for a list of codecs with static payload types. for a list of codecs with static payload types.
[32] ITU Q.2941-2, Digital Subscriber Signalling System No. 2 [32] ITU Q.2941-2, Digital Subscriber Signalling System No. 2
(DSS 2): Generic identifier transport extensions. (DSS 2): Generic identifier transport extensions.
[33] ITU Q.2961, Digital subscriber signalling system no.2 (DSS 2) [33] ITU Q.2961, Digital subscriber signalling system no.2 (DSS 2)
Rajesh Kumar, Mohamed Mostafa. 98
- additional traffic parameters. Also, Amendment 2 to Q.2961. - additional traffic parameters. Also, Amendment 2 to Q.2961.
[34] ITU Q. 2965.1, Digital subscriber signalling system no.2 (DSS 2) [34] ITU Q. 2965.1, Digital subscriber signalling system no.2 (DSS 2)
- Support of Quality of Service classes. - Support of Quality of Service classes.
Rajesh Kumar, Mohamed Mostafa. 94
[35] ITU Q. 2965.2, Digital subscriber signalling system no.2 (DSS 2) [35] ITU Q. 2965.2, Digital subscriber signalling system no.2 (DSS 2)
- Signalling of individual Quality of Service parameters. - Signalling of individual Quality of Service parameters.
[36] ITU Q.1901, Bearer Independent Call Control Protocol. [36] ITU Q.1901, Bearer Independent Call Control Protocol.
[37] ITU Q.2630.1, AAL type 2 signaling protocol - capability set 1. [37] ITU Q.2630.1, AAL type 2 signaling protocol - capability set 1.
[38] ITU I.363.5, B-ISDN ATM Adaptation Layer specification: Type 5 [38] ITU I.363.5, B-ISDN ATM Adaptation Layer specification: Type 5
AAL. AAL.
skipping to change at line 4891 skipping to change at line 5111
[49] rfc1305, Network Time Protocol, version 3. [49] rfc1305, Network Time Protocol, version 3.
[50] TIA/EIA/IS-J-STD-025-A, Lawfully Authorized Electronic Surveillance, [50] TIA/EIA/IS-J-STD-025-A, Lawfully Authorized Electronic Surveillance,
May 2000. May 2000.
[51] ITU-T H.222.1, Multimedia multiplex and synchronization for audiovisual [51] ITU-T H.222.1, Multimedia multiplex and synchronization for audiovisual
communication in ATM environments. communication in ATM environments.
[52] af-vmoa-0145.000, Voice and Multimedia over ATM, Loop Emulation Service [52] af-vmoa-0145.000, Voice and Multimedia over ATM, Loop Emulation Service
Rajesh Kumar, Mohamed Mostafa. 99
using AAL2. using AAL2.
[53] FRF.5, Frame Relay/ATM PVC Network Interworking Implementation Agreement. [53] FRF.5, Frame Relay/ATM PVC Network Interworking Implementation Agreement.
Rajesh Kumar, Mohamed Mostafa. 95
[54] FRF.8.1, Frame Relay/ATM PVC Service Interworking [54] FRF.8.1, Frame Relay/ATM PVC Service Interworking
Implementation Agreement. Implementation Agreement.
[55] FRF.11, Voice over Frame Relay Implementation Agreement. [55] FRF.11, Voice over Frame Relay Implementation Agreement.
[56] rfc2234, Augmented BNF for Syntax Specifications: ABNF. [56] rfc2234, Augmented BNF for Syntax Specifications: ABNF.
[57] ITU Q.765.5, Application Transport Mechanism - Bearer Independent [57] ITU Q.765.5, Application Transport Mechanism - Bearer Independent
Call Control. Call Control.
[58] http://www.3gpp.org/ftp/Specs for specifications related to 3GPP, [58] http://www.3gpp.org/ftp/Specs for specifications related to 3GPP,
including AMR codecs. including AMR codecs.
[59] ITU Q.931, Digital Subscriber Signaling System No. 1: Network Layer. [59] ITU Q.931, Digital Subscriber Signaling System No. 1: Network Layer.
[60] ITU Q.763, SS7 - ISUP formats and codes. [60] ITU Q.763, SS7 - ISUP formats and codes.
[61] http://www.atmforum.com/atmforum/specs/specs.html, ATM Forum, [61] http://www.atmforum.com/atmforum/specs/specs.html, ATM Forum,
Well-known addresses and assigned codes. Well-known addresses and assigned codes.
[62] rfc2119, Keywords for use in RFCs to indicate requirement levels.
Acknowledgements Acknowledgements
The authors wish to thank several colleagues at Cisco and in the The authors wish to thank several colleagues at Cisco and in the
industry who have contributed towards the development of these SDP industry who have contributed towards the development of these SDP
conventions, and who have reviewed, implemented and tested these conventions, and who have reviewed, implemented and tested these
constructs. Valuable technical ideas that have been incorporated constructs. Valuable technical ideas that have been incorporated
into this internet draft have been provided by Hisham Abdelhamid, into this internet draft have been provided by Hisham Abdelhamid,
Flemming Andreasen, David Auerbach, Robert Biskner, Bruce Buffam, Flemming Andreasen, David Auerbach, Robert Biskner, Bruce Buffam,
Steve Casner, Alex Clemm, Bill Foster, Snehal Karia, Raghu Thirumalai Steve Casner, Alex Clemm, Bill Foster, Snehal Karia, Raghu Thirumalai
Rajan, Joe Stone, Bruce Thompson, Dan Wing and Ken Young of Cisco, Rajan, Joe Stone, Bruce Thompson, Dan Wing and Ken Young of Cisco,
Michael Brown, Rade Gvozdanovic, Graeme Gibbs, Tom-PT Taylor, Mark Watson Michael Brown, Rade Gvozdanovic, Graeme Gibbs, Tom-PT Taylor, Mark Watson
and Sophia Scoggins of Nortel Networks, Brian Rosen, Tim Dwight and Michael and Sophia Scoggins of Nortel Networks, Brian Rosen, Tim Dwight and Michael
Mackey of Marconi, Ed Guy and Petros Mouchtaris of Telcordia, Christian Mackey of Marconi, Ed Guy and Petros Mouchtaris of Telcordia, Christian
Groves of Ericsson, Charles Eckel of Vovida Networks, Tom Jepsen, Groves of Ericsson, Charles Eckel of Vovida Networks, Tom Jepsen,
Dal Chohan, Sagar Gordhan and Chris Gallon of Fujitsu, Mahamood Dal Chohan, Sagar Gordhan and Chris Gallon of Fujitsu, Mahamood
Hussain of Hughes Software Systems and Sean Sheedy of nCUBE Hussain of Hughes Software Systems and Sean Sheedy of nCUBE
Corporation, Narendra Tulpule of Intel, and Albrecht Schwarz of Corporation, Narendra Tulpule of Intel, Albrecht Schwarz of Alcatel,
Alcatel. The authors also wish to thank the and Jonathan Rosenberg of Dynamicsoft. The authors also wish to thank the
ISC device control group, and the MMUSIC and MEGACO subgroups of the ISC device control group, and the MMUSIC and MEGACO subgroups of the
IETF, especially Bill Foster, Joerg Ott, Sean Sheedy and Brian Rosen IETF, especially Bill Foster, Joerg Ott, Sean Sheedy and Brian Rosen
for their help in the preparation of this document. Finally, thanks are for their help in the preparation of this document. Finally, thanks are
due to Narendra Tulpule of Intel whose ABNF grammar was adapted for due to Narendra Tulpule of Intel whose ABNF grammar was adapted for
this document. this document.
Rajesh Kumar, Mohamed Mostafa. 100
Authors' Addresses Authors' Addresses
Rajesh Kumar Rajesh Kumar
Cisco Systems, Inc. Cisco Systems, Inc.
M/S SJC01/3 M/S SJC01/3
170 West Tasman Drive 170 West Tasman Drive
San Jose, CA 95134-1706 San Jose, CA 95134-1706
Phone: 1-800-250-4800 Phone: 1-800-250-4800
Rajesh Kumar, Mohamed Mostafa. 96
Email: rkumar@cisco.com Email: rkumar@cisco.com
Mohamed Mostafa Mohamed Mostafa
Cisco Systems, Inc. Cisco Systems, Inc.
M/S SJC01/3 M/S SJC01/3
170 West Tasman Drive 170 West Tasman Drive
San Jose, CA 95134-1706 San Jose, CA 95134-1706
Phone: 1-800-250-4800 Phone: 1-800-250-4800
Email: mmostafa@cisco.com Email: mmostafa@cisco.com
Rajesh Kumar, Mohamed Mostafa. 97
Full Copyright Statement Full Copyright Statement
Copyright (C) The Internet Society (March 2, 2000). All Rights Copyright (C) The Internet Society (March 2, 2000). All Rights
Reserved. Reserved.
This document and translations of it may be copied and furnished to This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph kind, provided that the above copyright notice and this paragraph
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The limited permissions granted above are perpetual and will not be The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assigns. revoked by the Internet Society or its successors or assigns.
This document and the information contained herein is provided on an This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE." MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE."
Rajesh Kumar, Mohamed Mostafa. 98 Rajesh Kumar, Mohamed Mostafa. 101
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