draft-ietf-mmusic-sdp-atm-00.txt   draft-ietf-mmusic-sdp-atm-01.txt 
Internet Engineering Task Force Internet Engineering Task Force
Internet Draft Rajesh Kumar Internet Draft Rajesh Kumar
Document: draft-ietf-mmusic-sdp-atm-00.txt Mohamed Mostafa Document: draft-ietf-mmusic-sdp-atm-01.txt Mohamed Mostafa
September 12, 2000 Cisco Systems October 1, 2000 Cisco Systems
Expires: March 12, 2001 Expires: April 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
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strictly with the SDP syntax as defined in rfc2327. strictly with the SDP syntax as defined in rfc2327.
1. Introduction...............................................................2 1. Introduction...............................................................2
2. Representation of Certain Fields within SDP description lines..............4 2. Representation of Certain Fields within SDP description lines..............4
2.2 Representation of Parameter Values.....................................4 2.2 Representation of Parameter Values.....................................4
2.3 Directionality Convention..............................................4 2.3 Directionality Convention..............................................4
2.4 Case convention.........................................................5 2.4 Case convention.........................................................5
3. Capabilities Provided by SDP conventions..................................5 3. Capabilities Provided by SDP conventions..................................5
4. Format of the ATM Session Description......................................6 4. Format of the ATM Session Description......................................6
5.1 The Origin Line.........................................................8 5.1 The Origin Line.........................................................8
5.2 The Session Name Line...................................................9 5.2 The Session Name Line...................................................8
5.3 The Connection Information Line.........................................9 5.3 The Connection Information Line.........................................9
5.4 The Timestamp Line.....................................................10 5.4 The Timestamp Line.....................................................10
5.5 Media Information Line for ATM connections.............................11 5.5 Media Information Line for ATM connections.............................10
5.5.1 The Virtual Connection ID.........................................11 5.5.1 The Virtual Connection ID.........................................11
5.5.2 The Transport Parameter...........................................13 5.5.2 The Transport Parameter...........................................13
5.5.3 The Format List for AAL1 and AAL5 applications....................15 5.5.3 The Format List for AAL1 and AAL5 applications....................14
5.5.4 The Format List for AAL2 applications.............................15 5.5.4 The Format List for AAL2 applications.............................14
5.5.5 Media information line construction...............................14
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5.5.5 Media information line construction...............................15 5.6 The Media Attribute Lines..............................................17
5.6 The Media Attribute Lines..............................................18 5.6.1 The 'atmmap' attribute.......................................20
5.6.1 The 'atmmap' attribute.......................................21 5.6.2 The 'eecid' attribute............................................23
5.6.2 The 'eecid' attribute............................................24 5.6.3 The 'aalType' attribute............................................24
5.6.3 The 'aalType' attribute............................................25 5.6.4 The 'silenceSupp' attribute........................................24
5.6.4 The 'silenceSupp' attribute........................................25 5.6.5 The 'ecanf' and 'ecanb' attributes.................................25
5.6.5 The 'ecanf' and 'ecanb' attributes.................................26 5.6.6 The 'gcf' and 'gcb' attributes.....................................26
5.6.6 The 'gcf' and 'gcb' attributes.....................................27 5.6.7 The 'profileDesc' attribute........................................27
5.6.7 The 'profileDesc' attribute........................................28 5.6.8 The 'vsel' attribute...............................................28
5.6.8 The 'vsel' attribute...............................................29 5.6.9 The 'dsel' attribute...............................................29
5.6.9 The 'dsel' attribute...............................................30 5.6.10 The 'fsel' attribute..............................................30
5.6.10 The 'fsel' attribute..............................................31 5.6.11 The 'capability' attribute.......................................31
5.6.11 The 'capability' attribute.......................................32 5.6.12 The 'qosClass' attribute.........................................32
5.6.12 The 'qosClass' attribute.........................................33 5.6.13 The 'bcob' attribute.............................................32
5.6.13 The 'bcob' attribute.............................................33 5.6.14 The 'stc' attribute..............................................32
5.6.14 The 'stc' attribute..............................................33 5.6.15 The 'upcc' attribute.............................................33
5.6.15 The 'upcc' attribute.............................................34 5.6.16 The 'atmQOSfparms' and 'atmQOSbparms' attributes..................33
5.6.16 The 'atmQOSfparms' and 'atmQOSbparms' attributes..................34 5.6.17 The 'aal2QOSfparms' and 'aal2QOSbparms' attributes...............34
5.6.17 The 'aal2QOSfparms' and 'aal2QOSbparms' attributes...............35 5.6.18 The 'atmFtrfcDesc' and 'atmBtrfcDesc' attributes..................34
5.6.18 The 'atmFtrfcDesc' and 'atmBtrfcDesc' attributes..................35 5.6.19 The 'aal2FtrfcDesc' and 'aal2BtrfcDesc' attributes...............36
5.6.19 The 'aal2FtrfcDesc' and 'aal2BtrfcDesc' attributes...............37 5.6.20 The 'abrFparms' and 'abrBparms' attributes.......................36
5.6.20 The 'abrFparms' and 'abrBparms' attributes.......................37 5.6.21 The 'clkrec' attribute............................................37
5.6.21 The 'clkrec' attribute............................................38 5.6.23 The 'prtfl' attribute.............................................37
5.6.23 The 'prtfl' attribute.............................................38 5.6.24 The 'bearerType' attribute........................................38
5.6.24 The 'bearerType' attribute........................................39 5.6.25 The 'structure' attribute.........................................39
5.6.25 The 'structure' attribute.........................................40 5.6.26 The 'sbc' attribute...............................................39
5.6.26 The 'sbc' attribute...............................................40 5.6.27 The 'fcpsSDUsize' and 'bcpsSDUsize' attributes....................39
5.6.27 The 'fcpsSDUsize' and 'bcpsSDUsize' attributes....................40 5.6.28 The 'aal2CPS' attribute...........................................40
5.6.28 The 'aal2CPS' attribute...........................................41 5.6.29 The 'aal2sscs3661' attribute......................................40
5.6.29 The 'aal2sscs3661' attribute......................................41 5.6.30 The 'aal2sscs3662' attribute......................................41
5.6.30 The 'aal2sscs3662' attribute......................................42 5.6.31 The 'aalApp' attribute............................................42
5.6.31 The 'aalApp' attribute............................................43 5.6.32 The 'lij' attribute...............................................43
5.6.32 The 'lij' attribute...............................................44 5.6.34 The 'cache' attribute.............................................44
5.6.34 The 'cache' attribute.............................................45 5.6.35 Specification of Higher-layer attributes......................45
5.6.35 Specification of Higher-layer attributes......................46 5.6.36 Use of the second media-level part in H.323 Annex C applications45
5.6.36 Use of the second media-level part in H.323 Annex C applications46 5.6.37 Chaining SDP descriptors........................................46
5.6.37 Chaining SDP descriptors........................................47 5.6.38 Use of the eecid media attribute in call establishment procedures46
5.6.38 Use of the eecid media attribute in call establishment procedures47
6.0 List of Parameters with Representations...............................50 6.0 List of Parameters with Representations...............................50
7.0 Examples of ATM session descriptions using SDP.........................57 7.0 Examples of ATM session descriptions using SDP.........................56
8.0 Representation of data media..........................................58 8.0 Representation of data media..........................................57
9.0 Security Considerations..................................................59 9.0 Security Considerations..................................................58
9.1 Bearer Security.......................................................59 9.1 Bearer Security.......................................................58
9.2 Security of the SDP description.......................................59 9.2 Security of the SDP description.......................................58
10. ATM SDP Grammar..........................................................58
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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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
Parsers designed to this document should be flexible enough to Depending on the format of their representation in SDP, the
accommodate decimal and hexadecimal representations. The former parameters defined in this document fall into the following
do not have a prefix. The latter should use a "0x" prefix if values classes:
other than hexadecimal are permitted by the application. Even though
Section 6.0 of this document might allow both decimal and hexadecimal (1) Parameters always represented in a decimal format.
values, some applications might limit value representations to (2) Parameters always represented in a hexadecimal format.
hexadecimal or decimal. If only hex values are permitted, then the (3) Parameters always represented as character strings.
"0x" prefix can be safely omitted. (4) Parameters that can be represented in either decimal or
hexadecimal format.
No prefixes are needed for classes 1 - 3, since the format is
fixed. For class 4, a "0x" prefix shall always be used to
differentiate the hexadecimal from the decimal format.
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.
Generally, leading 0 digits are not used in either hexadecimal or decimal
representations. Exceptions are when an exact number of hex digits
is expected, as in the case of NSAP addresses. Parsers shall not
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.
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
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
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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
underlying ATM or AAL2 bearer. This simplicity comes at a price, underlying ATM or AAL2 bearer. This simplicity comes at a price,
described below. described below.
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The convention used by all ATM/AAL2 signaling specifications (e.g. Q.2931 The convention used by all ATM/AAL2 signaling specifications (e.g. Q.2931
Section 1.3.3 and Q.2630.1) mandates that forward direction is from the Section 1.3.3 and Q.2630.1) mandates that forward direction is from the
end initiating setup/establishment via bearer signaling towards the end end initiating setup/establishment via bearer signaling towards the end
receiving the setup/establishment request. The backward direction is in receiving the setup/establishment request. The backward direction is in
the opposite direction. In some cases, the 'forward' and 'backward' the opposite direction. In some cases, the 'forward' and 'backward'
directions of the ATM signaling convention might be the exact opposite of directions of the ATM signaling convention might be the exact opposite of
the SDP convention described above, requiring the media gateway to perform the SDP convention described above, requiring the media gateway to perform
the necessary translation. An example case in which this is needed is the necessary translation. An example case in which this is needed is
described below. described below.
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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.
* In AAL1/AAL5 applications, declaration of a set of payload * In AAL1/AAL5 applications, declaration of a set of payload
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types that can be bound to the ATM bearer connection. types that can be bound to the ATM bearer connection.
RTP payload types that have been registered with IANA are RTP payload types that have been registered with IANA are
re-used for AAL1 or AAL5 [31]. In the manner of standard SDP, re-used for AAL1 or AAL5 [31]. In the manner of standard SDP,
unregistered payload types are mapped dynamically. unregistered payload types are mapped dynamically.
* In AAL2 applications, declaration of a set of profiles that * In AAL2 applications, declaration of a set of profiles that
can be bound to the ATM bearer connection. A mechanism for can be bound to the ATM bearer connection. A mechanism for
dynamically defining custom profiles within the SDP session dynamically defining custom profiles within the SDP session
description is included. This allows the use of custom description is included. This allows the use of custom
profiles for connections that span multi-network interfaces. profiles for connections that span multi-network interfaces.
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* A means of correlating service-level connections with * A means of correlating service-level connections with
underlying ATM bearer connections. The backbone network underlying ATM bearer connections. The backbone network
connection identifier or bnc-id specified in ITU Q.1901 [36] connection identifier or bnc-id specified in ITU Q.1901 [36]
standardization work is used for this purpose. In order to standardization work is used for this purpose. In order to
provide a common SDP base for applications based on provide a common SDP base for applications based on
Q.1901 and SIP/SIP+, the neutral term 'eecid' is used Q.1901 and SIP/SIP+, the neutral term 'eecid' is used
in lieu of 'bnc-id' in the SDP session descriptor. in lieu of 'bnc-id' in the SDP session descriptor.
* A means of mapping codec types and packetization periods into * A means of mapping codec types and packetization periods into
service types (voice, voiceband data and facsimile). This is service types (voice, voiceband data and facsimile). This is
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and port number on which the node will receive RTCP messages. and port number on which the node will receive RTCP messages.
* 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.
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
medium and RTCP control (where applicable). bearer medium and RTCP control (where applicable).
Session descriptor with one media-level part: The session level part consists of the following lines:
v= (protocol version, zero or one line) v= (protocol version, zero or one line)
o= (origin, zero or one line) o= (origin, zero or one line)
s= (session name, zero or one line) s= (session name, zero or one line)
c= (connection information, one line) c= (connection information, one line)
b= (bandwidth, zero or more lines)
t= (timestamp, zero or one line) t= (timestamp, zero or one line)
m= (media information and transport address, one line)
b= (bandwidth, zero or one line)
k= (encryption key, zero or one line) k= (encryption key, zero or one line)
a= (media attribute, zero or more lines)
Session descriptor with two media-level parts (used in h.323 annex C In ATM session descriptions, there are no media attribute lines in the
applications): session level part. These are present in the media-level parts.
Session-level part
v= (protocol version, zero or one line)
o= (origin, zero or one line)
s= (session name, zero or one line)
c= (connection information, one line)
t= (timestamp, zero or one line)
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media-level part (audio medium) The media level part for the ATM bearer consists of the following
lines:
m= (media information and transport address, one line) m= (media information and transport address, one line)
b= (bandwidth, zero or one line) b= (bandwidth, zero or more lines)
k= (encryption key, zero or one line) k= (encryption key, zero or more lines)
a= (media attribute, zero or more lines) a= (media attribute, zero or more lines)
media-level part (control medium) The media level part for RTCP control consists of the following
lines:
m= (media information and transport address, one line) m= (media information and transport address, one line)
c= (connection information for control only, one line) c= (connection information for control only, one line)
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].
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- Different layers of the same session (section 5.6.37). - Different layers of the same session (section 5.6.37).
The 'o', 's' and 't' lines are included for strict conformance with The 'o', 's' and 't' lines are included for strict conformance with
RFC2327. It is possible that these lines might not carry useful RFC2327. It is possible that these lines might not carry useful
information in some ATM-based applications. information in some ATM-based applications.
Therefore, some applications might omit these lines, although Therefore, some applications might omit these lines, although
it is recommended that they not do so. For maximum it is recommended that they not do so. For maximum
interoperability, it is preferable that SDP parsers not interoperability, it is preferable that SDP parsers not
reject session descriptions that do not contain these lines. reject session descriptions that do not contain these lines.
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5. Structure of the Session Description Lines 5. Structure of the Session Description Lines
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5.1 The Origin Line 5.1 The Origin Line
The origin line for an ATM-based session is structured as follows: The origin line for an ATM-based session is structured as follows:
o=<username> <sessionID><version> <networkType> o=<username> <sessionID><version> <networkType>
<ATMaddressType> <ATMaddress> <ATMaddressType> <ATMaddress>
The <username> is set to "-". The <username> is set to "-".
The <sessionID> can be set to one of the following: The <sessionID> can be set to one of the following:
* an NTP timestamp referring to the moment when the SDP session * an NTP timestamp referring to the moment when the SDP session
descriptor was created. descriptor was created.
* a Call ID, connection ID or context ID that uniquely * a Call ID, connection ID or context ID that uniquely
identifies the session within the scope of the ATM node. identifies the session within the scope of the ATM node.
Since calls can comprise multiple connections (sessions), Since calls can comprise multiple connections (sessions),
call IDs are generally not suitable for this purpose. call IDs are generally not suitable for this purpose.
NTP time stamps can be represented as decimal or hex integers. NTP time stamps can be represented as decimal or hex integers.
The part of the NTP timestamp that refers to an integer number The part of the NTP timestamp that refers to an integer number
of seconds is sufficient. Since this is a 32-bit field, the decimal of seconds is sufficient. This is a 32-bit field
or hex equivalent of a 32-bit field is adequate if NTP time stamps
are used for this purpose.
On the other hand, call IDs, connection IDs and context IDs can be On the other hand, call IDs, connection IDs and context IDs can be
represented in decimal or hex format, or as a string of alphanumeric can be 32 hex digits long.
characters. The MGCP connection ID can be 32 hex digits long.
In general, to cover all cases, the <sessionID> can comprise of up to The <sessionID> field is represented as a decimal or hex number of
34 alphanumeric characters. The additional two characters allow the up to 32 digits. A "0x" prefix is used before the hex representation.
inclusion of a "0x" prefix before 32 hex digits.
The <version> refers to the version of the SDP session descriptor The <version> refers to the version of the SDP session descriptor
(not that of the SDP protocol). This is can be set to one of the (not that of the SDP protocol). This is can be set to one of the
following: following:
* 0. * 0.
* an NTP timestamp referring to the moment when the SDP session * an NTP timestamp referring to the moment when the SDP session
descriptor was modified. If the SDP session descriptor has not descriptor was modified. If the SDP session descriptor has not
been modified by an intermediate entity (such as an MGC), been modified by an intermediate entity (such as an MGC),
then the <version> timestamp will be the same as the <sessionId> then the <version> timestamp will be the same as the <sessionId>
timestamp, if any. As with the <sessionId>, only the integer part timestamp, if any. As with the <sessionId>, only the integer part
of the NTP timestamp is used. of the NTP timestamp is used.
It is adequate to allow up to 10 decimal or 8 hex digits for the When equated to the integer part of an NTP timestamp, the <version> field
<version>. This is enough to represent the integer part of an NTP is 10 digits wide. This is more restricted than [1], which allows unlimited
timestamp. size. As in [1], the most significant digit is non-zero when an NTP
timestamp is used.
The <networkType> in SDP session descriptions for ATM applications The <networkType> in SDP session descriptions for ATM applications
should be assigned the string value "ATM". should be assigned the string value "ATM".
The <ATMaddressType> and <ATMaddress> parameters are identical to The <ATMaddressType> and <ATMaddress> parameters are identical to
those for the connection information ('c') line. Each of these those for the connection information ('c') line. Each of these
parameters can be set to a "-". However, it is not recommended parameters can be set to a "-". However, it is not recommended
that these fields be omitted without being set to a "-" since that these fields be omitted without being set to a "-" since
this is not explicitly allowed by standard SDP (rfc2327). It this is not explicitly allowed by standard SDP (rfc2327). It
is recognized that some parser-builders follow this practice. is recognized that some parser-builders follow this practice.
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5.2 The Session Name Line 5.2 The Session Name Line
In general, the session name line is structured as follows: In general, the session name line is structured as follows:
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s=<sessionName> s=<sessionName>
For ATM-based sessions, the <sessionName> parameter is set to a "-". For ATM-based sessions, the <sessionName> parameter is set to a "-".
The resulting line is: The resulting line is:
s=- s=-
It is not recommended that the <sessionName> be omitted without
being set to a "-" since this is not explicitly allowed by
standard SDP (rfc2327). It is recognized that some parser-builders
follow this practice.
5.3 The Connection Information Line 5.3 The Connection Information Line
The connection information line for ATM-based sessions is structured The connection information line for ATM-based sessions is structured
as follows: as follows:
c=<networkType> <ATMaddressType> <ATMaddress> c=<networkType> <ATMaddressType> <ATMaddress>
The <networkType> field in the 'c' line should be set to "ATM". The <networkType> field in the 'c' line should be set to "ATM".
When the SDP description is built by an ATM node such as a media gateway, When the SDP description is built by an ATM node such as a media gateway,
skipping to change at line 531 skipping to change at line 529
the local descriptor are each set to "-". the local descriptor are each set to "-".
Additionally, in all contexts, the 'm' line can have an ATM address in the 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.
The <ATMaddressType> can be NSAP, E164 or GWID (ALIAS). The <ATMaddressType> can be NSAP, E164 or GWID (ALIAS).
The <ATMaddress> format depends on the <ATMaddressType>. The <ATMaddress> format depends on the <ATMaddressType>.
NSAP: If the ATMaddressType is NSAP, the ATMaddress is expressed as NSAP: If the ATMaddressType is NSAP, the ATMaddress is expressed in
a string of 40 hex characters without the "0x" prefix. As an option, the standard dotted hex form. This is a string of 40 hex digits,
dots can be included after 16-bit fields, with the first dot following with dots after the 2nd, 6th, 10th, 14th, 18th, 22nd, 26th, 30th,
an 8-bit field (standard dotted hex NSAP format). The last octet of the NSAP 34th and 38th digits. The last octet of the NSAP address is the
address is the 'selector' field that is not used for ATM addressing 'selector' field that is available for non-standard use. An example
and is available for non-standard use. For example: 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
hexadecimal format.
E164: If the ATMaddressType is E164, the ATMaddress is expressed as E164: If the ATMaddressType is E164, the ATMaddress 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
The use of E.164 numbers in the B-ISDN context is defined in ITU E.191. The use of E.164 numbers in the B-ISDN context is defined in ITU E.191.
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
Rajesh Kumar, Mohamed Mostafa. 9
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
Rajesh Kumar, Mohamed Mostafa. 9
E.164 International Format. E.164 International Format.
GWID (ALIAS): If the ATMaddressType is GWID meaning that the address is a GWID (ALIAS): If the ATMaddressType is GWID meaning 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 ATMaddress is expressed as alphanumeric string In this case, the ATMaddress is expressed as 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 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. Some network administrations might restrict it to a smaller characters.
size (e.g. 15 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, if there is no address to transmit, this line descriptor. However, if there is no address to transmit, this line
can be represented in the following way: can be represented in one of the following ways:
c=ATM - - c=ATM - -
c=ATM $ $
c=ATM <ATMaddressType> -
c=ATM <ATMaddressType> $
This might be used when the address is known a priori. It is not Specifying the ATM address type without specifying the ATM address
recommended that <ATMaddressType> or <ATMaddress> be omitted is useful when the recipient is asked to select an ATM address of
without being set to a "-" since this is not explicitly allowed a certain type (NSAP, E.164 etc.).
by standard SDP (rfc2327). It is recognized that some parser-builders
follow this practice. <ATMaddressType> and/or <ATMaddress> should not omitted
without being set to a "-" or "$" since this would violate basic
SDP syntax [1].
5.4 The Timestamp Line 5.4 The Timestamp Line
The timestamp line for an SDP session descriptor is structured as The timestamp line for an SDP session descriptor is structured as
follows: follows:
t= <startTime> <stopTime> t= <startTime> <stopTime>
For ATM-based sessions, the <startTime>parameter can be made equal to Per Ref. [49], NTP time stamps use a 32 bit unsigned
the NTP timestamp (if any) used for the <sessionID> in the 'o' line. It
can also be set to 0 indicating its irrelevance. If it made equal to the NTP
timestamp in seconds, the fractional part of the NTP timestamp is omitted.
In this case, it is adequate to allow the hex or decimal equivalent of
a 32-bit field. 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. fractional seconds. For ATM-based sessions, the <startTime>parameter can
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
indicating its irrelevance. If it made equal to the NTP
timestamp in seconds, the fractional part of the NTP timestamp is omitted.
When equated to the integer part of an NTP timestamp, the <startTime>
field is 10 digits wide. This is more restricted than [1], which
allows unlimited size. As in [1], the most significant digit is
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.
Rajesh Kumar, Mohamed Mostafa. 10
5.5 Media Information Line for ATM connections 5.5 Media Information Line for ATM connections
Rajesh Kumar, Mohamed Mostafa. 10
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:
m=<media> <virtualConnectionId> <transport> <format list> m=<media> <virtualConnectionId> <transport> <format list>
The general format of the media information line adapted for AAL2 The general format of the media information line adapted for AAL2
applications is: applications is:
m=<media> <virtualConnectionId> <transport#1> <format list#1> m=<media> <virtualConnectionId> <transport#1> <format list#1>
<transport#2> <format list#2> ... <transport#M> <format list#M> <transport#2> <format list#2> ... <transport#M> <format list#M>
skipping to change at line 633 skipping to change at line 640
The subparameter <media> can take on all the values defined in [1]. The subparameter <media> can take on all the values defined in [1].
These are: "audio", "video", "application", "data" and "control". These are: "audio", "video", "application", "data" and "control".
When the <transport> parameter has more than one value in the 'm' When the <transport> parameter has more than one value in the 'm'
line, the <transport> <format list> pairs can be arranged in line, the <transport> <format list> pairs can be arranged in
preferential order. preferential order.
5.5.1 The Virtual Connection ID 5.5.1 The Virtual Connection ID
The <virtualConnectionId> parameter can be in one of two basic formats: The <virtualConnectionId> in AAL1 and AAL5 applications can be in
with explicit designation of subparameter types within the one of the following formats:
<virtualConnectionId> parameter, or with implicit inference of subparameter
type from subparameter position in the <virtualConnectionId> parameter. In
general, explicit designation is recommended for open, interoperable, large-
scale applications. However, implicit designation is retained as a shortcut
in smaller applications where the number of options is limited and the
subparameter type can be inferred unambiguously from its position relative
to slashes and hyphens, if any. This narrowing of options can be done on
the basis of embedded defaults or prior provisioning. Likewise, in some
cases of implicit designation, omitted ATM address types are known by
default or through provisioning.
With implicit inference of subparameter type from subparameter position,
the AAL1 or AAL5 <virtualConnectionId> can be in one of the following
formats (parameter definitions provided later):
* <vcci>
* <ATMaddressType>-<ATMaddress>/<vcci>
* <ATMaddress>/<vcci>
* <bcg>/<vcci>
* <portId>/<vpi>/<vci>
* <bcg>/<vpi>/<vci>
* <vpci>/<vci>
* <ATMaddressType>-<ATMaddress>/<vpci>/<vci>
* <ATMaddress>/<vpci>/<vci>
With implicit inference of subparameter type from subparameter position,
the AAL2 <virtualConnectionId> can be in one of the following
formats (parameter definitions provided later):
* <vcci>/<cid>
* <ATMaddressType>-<ATMaddress>/<vcci>/<cid>
* <ATMaddress>/<vcci>/<cid>
* <bcg>/<vcci>/<cid>
* <portId>/<vpi>/<vci>/<cid>
* <bcg>/<vpi>/<vci>/<cid>
Rajesh Kumar, Mohamed Mostafa. 11
* <vpci>/<vci>/<cid>
* <ATMaddressType>-<ATMaddress>/<vpci>/<vci>/<cid>
* <ATMaddress>/<vpci>/<vci>/<cid>
With explicit designation of subparameter types, the <virtualConnectionId>
in AAL1 and AAL5 applications can be in one of the following formats
(parameter definitions provided later):
* <ex_vcci> * <ex_vcci>
* <ATMaddressType>-<ATMaddress>/<ex_vcci> * <ATMaddressType>-<ATMaddress>/<ex_vcci>
* <ATMaddress>/<ex_vcci> * <ATMaddress>/<ex_vcci>
* <ex_bcg>/<ex_vcci> * <ex_bcg>/<ex_vcci>
* <ex_portId>/<ex_vpi>/<ex_vci> * <ex_portId>/<ex_vpi>/<ex_vci>
* <ex_bcg>/<ex_vpi>/<ex_vci> * <ex_bcg>/<ex_vpi>/<ex_vci>
* <ex_vpci>/<ex_vci> * <ex_vpci>/<ex_vci>
* <ATMaddressType>-<ATMaddress>/<ex_vpci>/<ex_vci> * <ATMaddressType>-<ATMaddress>/<ex_vpci>/<ex_vci>
* <ATMaddress>/<ex_vpci>/<ex_vci> * <ATMaddress>/<ex_vpci>/<ex_vci>
The <virtualConnectionId> in AAL2 applications can be in one of the
With explicit designation of subparameter types, the <virtualConnectionId> following formats:
in AAL2 applications can be in one of the following formats
(parameter definitions provided later):
* <ex_vcci>/<ex_cid> * <ex_vcci>/<ex_cid>
* <ATMaddressType>-<ATMaddress>/<ex_vcci>/<ex_cid> * <ATMaddressType>-<ATMaddress>/<ex_vcci>/<ex_cid>
* <ATMaddress>/<ex_vcci>/<ex_cid> * <ATMaddress>/<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> * <ex_vpci>/<ex_vci>/<ex_cid>
* <ATMaddressType>-<ATMaddress>/<ex_vpci>/<ex_vci>/<ex_cid> * <ATMaddressType>-<ATMaddress>/<ex_vpci>/<ex_vci>/<ex_cid>
* <ATMaddress>/<ex_vpci>/<ex_vci>/<ex_cid> * <ATMaddress>/<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>
<ex_cid> = CID-<cid> <ex_cid> = CID-<cid>
The <vcci>, <portId>, <vpi>, <vci>, <vpci> and <cid> are decimal numbers The <vcci>, <vpi>, <vci>, <vpci> and <cid> are decimal numbers
or hexadecimal numbers. The <ATMaddressType> and <ATMaddress> are identical or hexadecimal numbers. An "0x" prefix is used before their values
when they are in the hex format.
The <portId> is always a hexadecimal number. An "0x" prefix is not used
Rajesh Kumar, Mohamed Mostafa. 11
with it.
The <ATMaddressType> and <ATMaddress> are identical
to their definitions above for the connection information line with to their definitions above for the connection information line with
the difference that this address refers to the remote peer in the the difference that this address refers to the remote peer in the
media information line. media information line.
The <vpi>, <vci> and <cid> have their usual ATM connotation. The <vpi>, <vci> and <cid> have their usual ATM connotation. The
<vpi> is an 8 or 12 bit field. The <vci> is a 16 bit field. The <cid>
is an 8 bit field.
The <vpci> is a 16 bit field defined in Section 4.5.16 of ITU The <vpci> is a 16 bit field defined in Section 4.5.16 of ITU
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 Since <vpci> and <vcci> values are unique between a pair of nodes, they
Rajesh Kumar, Mohamed Mostafa. 12
need to be qualified, at any node, by the ATM address of the remote node. 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
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
dynamically assigned to calls. One such scheme for glare reduction is the dynamically assigned to calls. One such scheme for glare reduction is the
skipping to change at line 761 skipping to change at line 730
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.
The <portId> parameter is used to identify the physical trunk port The <portId> parameter is used to identify the physical trunk port
on a stand-alone ATM node or on a multiplexer into which the on an ATM module. It can be represented as a hexadecimal number of
gateway is plugged as a tributary module. It can be represented as a up to 32 hex digits.
decimal or hex number of up to 32 digits, or an alphanumeric string of
up to 32 characters. In general, to cover all cases, the <portID>
can consist of up to 34 alphanumeric characters. The additional two
characters allow the inclusion of a "0x" prefix for hex digits.
In some applications, it is meaningful to bundle a set of connections In some applications, it is meaningful to bundle a set of connections
between a pair of ATM nodes into a bearer connection group. The <bcg> between a pair of ATM nodes into a bearer connection group. The <bcg>
subparameter is an eight bit field that allows the bundling of up subparameter is an eight bit field that allows the bundling of up
to 255 VPCs or VCCs. to 255 VPCs or VCCs.
In some applications, it is necessary to wildcard the <virtualConnectionId> In some applications, it is necessary to wildcard the <virtualConnectionId>
parameter, or some elements of this parameter. The "$" wildcard character parameter, or some elements of this parameter. The "$" wildcard character
can be substituted for the entire <virtualConnectionId> parameter, or some can be substituted for the entire <virtualConnectionId> parameter, or some
of its terms. A wildcarded <virtualConnectionId> can use the explicit or of its terms. In the latter case, the constant strings that
implicit formats described above. In the former, the constant strings that
Rajesh Kumar, Mohamed Mostafa. 12
qualify the terms in the <virtualConnectionId> are retained. The qualify the terms in the <virtualConnectionId> are retained. The
concatenation <ATMaddressType>-<ATMaddress> can be wildcarded in the concatenation <ATMaddressType>-<ATMaddress> can be wildcarded in the
following ways: following ways:
* The entire concatenation, <ATMaddressType>-<ATMaddress>, is * The entire concatenation, <ATMaddressType>-<ATMaddress>, is
replaced with a "$". replaced with a "$".
* <ATMaddress> is replaced with a "$", but <ATMaddressType> is * <ATMaddress> is replaced with a "$", but <ATMaddressType> is
not. not.
Examples of wildcarding the <virtualConnectionId> in the AAL1 and AAL5 Examples of wildcarding the <virtualConnectionId> in the AAL1 and AAL5
contexts are: $, 62/$, 100/20/$, VCCI-$, 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: $, 62/$, wildcarding the <virtualConnectionId> in the AAL2 context are: $,
100/20/$, VCCI-40/CID-$, BCG-100/VPI-20/VCI-120/CID-$. VCCI-40/CID-$, BCG-100/VPI-20/VCI-120/CID-$, NSAP-$/VCCI-$/CID-$,
$/VCCI-$/CID-$.
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
Rajesh Kumar, Mohamed Mostafa. 13
refer to other standards. For ATM applications, the following refer to other standards. For ATM applications, the following
<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] |
+------------------------+--------------------------------------------+ +------------------------+--------------------------------------------+
skipping to change at line 840 skipping to change at line 805
| RTP/AVP | Annex C of H.323 [45] | | RTP/AVP | Annex C of H.323 [45] |
+------------------------+--------------------------------------------+ +------------------------+--------------------------------------------+
In H.323 Annex C applications [45], the <transport> parameter has a In H.323 Annex C applications [45], the <transport> parameter has a
value of "RTP/AVP". This is because these applications use the RTP value of "RTP/AVP". This is because these applications use the RTP
protocol [2] and audio/video profile [3]. The fact that RTP is carried protocol [2] and audio/video profile [3]. The fact that RTP is carried
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
Rajesh Kumar, Mohamed Mostafa. 13
<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.
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.
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 is not used. For example, "IEEE:00000C" is one of the <oui> values prefix shall not be used. For example, "IEEE:00000C" is one of the
that refers to Cisco Systems, Inc. <oui> values that refers to Cisco Systems, Inc.
Rajesh Kumar, Mohamed Mostafa. 14
5.5.3 The Format List for AAL1 and AAL5 applications 5.5.3 The Format List for AAL1 and AAL5 applications
In the AAL1 and AAL5 contexts, the <format list> is a list of payload In the AAL1 and AAL5 contexts, the <format list> is a list of payload
types: types:
<payloadType#1> <payloadType#2>...<payloadType#n> <payloadType#1> <payloadType#2>...<payloadType#n>
In most AAL1 and AAL5 applications, the ordering of payload types In most AAL1 and AAL5 applications, the ordering of payload types
implies a preference (preferred payload types before less favored implies a preference (preferred payload types before less favored
skipping to change at line 903 skipping to change at line 868
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.
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>
Rajesh Kumar, Mohamed Mostafa. 14
<payloadType#2>...<payloadType #n> <payloadType#2>...<payloadType #n>
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:
m=audio VCCI-27 AAL1/ATMF 0 m=audio VCCI-27 AAL1/ATMF 0
This indicates the use of an AAL1 VCC with VCCI=24 to carry PCMU audio This indicates the use of an AAL1 VCC with VCCI=24 to carry PCMU audio
Rajesh Kumar, Mohamed Mostafa. 15
that is encapsulated according to ATMF's af-vtoa-78 [7]. that is encapsulated according to ATMF's af-vtoa-78 [7].
Another example of the use of the 'm' line use for audio media over AAL1 Another example of the use of the 'm' line use for audio media over AAL1
is: is:
m=audio $ AAL1/ATMF 0 8 m=audio $ AAL1/ATMF 0 8
This indicates that any AAL1 VCC may be used. If it exists already, then This indicates that any AAL1 VCC may be used. If it exists already, then
its selection is subject to glare rules. The audio media on this VCC its selection is subject to glare rules. The audio media on this VCC
is encapsulated according to ATMF's af-vtoa-78 [7]. The encodings to be is encapsulated according to ATMF's af-vtoa-78 [7]. The encodings to be
used are either PCMU or PCMA, in preferential order. used are either PCMU or PCMA, in preferential order.
In some applications, an "-" can be used in lieu of the <payloadType> and
<transport>. This implies that the encoding scheme and encapsulation method
are described elsewhere, or defaulted. For example:
m=audio VCCI-234 - -
a=aalType:AAL1
indicates the use of VCCI=234 with AAL1 adaptation and unspecified encoding.
The 'm' for AAL5-based audio media can be constructed as The 'm' for AAL5-based audio media can be constructed as
follows: follows:
m=audio <virtualConnectionId> AAL5/ATMF <payloadType#1> m=audio <virtualConnectionId> AAL5/ATMF <payloadType#1>
<payloadType#2>...<payloadType #n> <payloadType#2>...<payloadType #n>
An example 'm' line use for audio media over AAL5 is: An example 'm' line use for audio media over AAL5 is:
m=audio 2/6/$ AAL5/ITU 9 15 m=audio PORT-2/VPI-6/$ AAL5/ITU 9 15
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:
skipping to change at line 974 skipping to change at line 930
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
a=aalApp:h323c a=aalApp: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
Rajesh Kumar, Mohamed Mostafa. 15
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' for AAL5-based video media can be constructed as follows: The 'm' for AAL5-based video media can be constructed as follows:
m=video <virtualConnectionId> AAL5/ITU <payloadType#1> m=video <virtualConnectionId> AAL5/ITU <payloadType#1>
<payloadType#2>...<payloadType #n> <payloadType#2>...<payloadType #n>
Rajesh Kumar, Mohamed Mostafa. 16
In this case, the use of AAL5/ITU as the transport points to H.222.1 In this case, the use of AAL5/ITU as the transport points to H.222.1
as the controlling standard [51].An example 'm' line use for video media as the controlling standard [51].An example 'm' line use for video media
is: is:
m=video PORT-9/VPI-3/VCI-$ AAL5/ITU 33 m=video PORT-9/VPI-3/VCI-$ AAL5/ITU 33
This indicates that any VCI on VPI= 3 of trunk port #9 may be used. This indicates that any VCI on VPI= 3 of trunk port #9 may be used.
The video media on this VCC is encapsulated according to ITU-T The video media on this VCC is encapsulated according to ITU-T
H.222.1 [51]. The encoding scheme is an MPEG 2 transport stream ("MP2T" H.222.1 [51]. The encoding scheme is an MPEG 2 transport stream ("MP2T"
in Table 1). This is statically mapped per [31] to a payload type of 33. in Table 1). This is statically mapped per [31] to a payload type of 33.
skipping to change at line 1036 skipping to change at line 993
An example 'm' line use for audio media over AAL2 is: An example 'm' line use for audio media over AAL2 is:
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. 16
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
Rajesh Kumar, Mohamed Mostafa. 17
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>
category "AAL2/ATMF". This application does not order profiles category "AAL2/ATMF". This application does not order profiles
preferentially. This rule is known a priori. It is not embedded in the 'm' preferentially. This rule is known a priori. It is not embedded in the 'm'
line. line.
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-20/CID-$ AAL2/xyzCorporation 11 m=audio VCCI-20/CID-$ AAL2/xyzCorporation 11
AAL2 VCCs in this application are single-CID VCCs. Therefore, it is possible AAL2 VCCs in this application are single-CID VCCs. Therefore, it is possible
to wildcard the CID. The single-CID VCC with VCCI=20 is selected. The AAL2 to wildcard the CID. The single-CID VCC with VCCI=20 is selected. The AAL2
profile to be used is AAL2/xyzCorporation 11 defined by xyzCorporation. profile to be used is AAL2/xyzCorporation 11 defined by xyzCorporation.
In some applications, an "-" can be used in lieu of the <transport> In some applications, an "-" can be used in lieu of:
and <profile#> fields. This is possible when the coding scheme is - <format list>
described elsewhere e.g. when 'aal2sscs3662' attribute indicates - <transport> and <format list>
This implies that these parameters are irrelevant or are known by
other means (such as defaults). For example:
m=audio VCCI-234 - -
a=aalType:AAL1
indicates the use of VCCI=234 with AAL1 adaptation and unspecified encoding.
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 indicates AAL2. An example of the use of the 'm' line <aalType> attribute can indicate AAL2. Thus:
in this case is:
m=audio 123/5 - - 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,
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.
5.6 The Media Attribute Lines 5.6 The Media Attribute Lines
In an SDP line sequence, the media information line 'm' is In an SDP line sequence, the media information line 'm' is
followed by one or more media attribute or 'a' lines. Media followed by one or more media attribute or 'a' lines. Media
attribute lines are per the format below: attribute lines are per the format below:
a=<attribute>:<value> a=<attribute>:<value>
or or
a=<value> a=<value>
Rajesh Kumar, Mohamed Mostafa. 17
In general, media attribute lines are optional except when needed to In general, media attribute lines are optional except when needed to
qualify the media information line. This qualification is necessary qualify the media information line. This qualification is necessary
when the "m" line for an AAL1 or AAL5 session specifies a payload when the "m" line for an AAL1 or AAL5 session specifies a payload
type that needs to be dynamically mapped. The 'atmmap' media type that needs to be dynamically mapped. The 'atmmap' media
attribute line defined below is used for this purpose. attribute line defined below is used for this purpose.
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
must not contradict each other or the other SDP lines. Inconsistencies must not contradict each other or the other SDP lines. Inconsistencies
Rajesh Kumar, Mohamed Mostafa. 18
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. However, describing the general attributes of ATM bearer networks.
it is recognized that this list might have overlooked some attributes,
which particular applications might need. If these are common
enough for general interoperability between vendors (as opposed
to innovation and proprietary differentiation by particular
vendors), then these should be brought to the attention of the
IETF MMUSIC working group or the authors for incorporation into the
RFC that will evolve out of this document.
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 in the ATM context. Detailed descriptions of these attributes be used in the ATM context. Detailed descriptions of these attributes
are to be found in subsequent sections. are to be found in subsequent sections.
* The attributes defined in RFC2327 which allow indication of * The attributes defined in RFC2327 which allow indication of
the direction in which a session is active. These are the direction in which a session is active. These are
a=sendonly, a=recvonly, a=sendrecv, a=inactive. a=sendonly, a=recvonly, a=sendrecv, a=inactive.
* The 'Ptime' attribute defined in RFC2327. It indicates the * The 'Ptime' attribute defined in RFC2327. It indicates the
packet period. It is not recommended that this attribute be used packet period. It is not recommended that this attribute be used
skipping to change at line 1160 skipping to change at line 1116
optionally parameterize the silence suppression function. optionally parameterize the silence suppression function.
* The 'ecanf' and 'ecanb' attributes, used to indicate the use of * The 'ecanf' and 'ecanb' attributes, 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 'gcf' and 'gcb' attributes, 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
Rajesh Kumar, Mohamed Mostafa. 18
only. only.
* The 'vsel' attribute which indicates a prioritized list of * The 'vsel' attribute which indicates a prioritized list of
3-tuples for voice service. Each 3-tuple indicates a codec, 3-tuples for voice service. 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.
* 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
Rajesh Kumar, Mohamed Mostafa. 19
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
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 '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).
skipping to change at line 1223 skipping to change at line 1179
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.
* When present, the 'structure' attribute is used to indicate * When present, the 'structure' attribute 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.
* When present, the 'sbc' media attribute line denotes the * When present, the 'sbc' media attribute line 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.
* When present, the 'fcpsSDUsize' and 'bcpsSDUsize' * When present, the 'fcpsSDUsize' and 'bcpsSDUsize'
attributes are used to indicate the maximum size of the attributes are used to indicate the maximum size of the
Rajesh Kumar, Mohamed Mostafa. 19
CPCS SDU payload in the forward and backward directions. CPCS SDU payload in the forward and backward directions.
* When present, the 'aal2CPS' attribute is used to * When present, the 'aal2CPS' attribute 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.
* When present, the 'aal2sscs3661' attribute is used to * When present, the 'aal2sscs3661' attribute is used to
indicate the presence of an AAL2 SSCS sublayer as defined indicate the presence of an AAL2 SSCS sublayer as defined
in ITU I.366.1 [12]. Optionally, it can be used to indicate in ITU I.366.1 [12]. Optionally, it can be used to indicate
Rajesh Kumar, Mohamed Mostafa. 20
selected options and parameter values for this SSCS. selected options and parameter values for this SSCS.
* When present, the 'aal2sscs3662' attribute is used to * When present, the 'aal2sscs3662' attribute is used to
indicate the presence of an AAL2 SSCS sublayer as defined indicate the presence of an AAL2 SSCS sublayer as defined
in ITU I.366.2. Optionally, it can be used to indicate in ITU I.366.2. Optionally, it can be used to indicate
selected options and parameter values for this SSCS. selected options and parameter values for this SSCS.
* 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 controlling standard for an application layer above the ATM
adaptation layer. adaptation layer.
* When present, the 'lij' attribute is used to indicate the * When present, the 'lij' attribute 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
skipping to change at line 1285 skipping to change at line 1241
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.
Table 2 lists standard encoding names with their corresponding statically Table 2 lists standard encoding names with their corresponding statically
mapped payload types [31]. It also suggests encoding names for mapped payload types [31]. It also suggests encoding names for
codecs not addressed in [31]. For these, payload types are mapped codecs not addressed in [31]. For these, payload types are mapped
dynamically via the 'atmmap' attribute. Table 2 is not meant to be an dynamically via the 'atmmap' attribute. Table 2 is not meant to be an
exhaustive list of codec names. exhaustive list of codec names.
Rajesh Kumar, Mohamed Mostafa. 21 Rajesh Kumar, Mohamed Mostafa. 20
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 1344 skipping to change at line 1300
| suppression | | | | suppression | | |
|----------------------------------------------------------------| |----------------------------------------------------------------|
| 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 |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
Rajesh Kumar, Mohamed Mostafa. 22 Rajesh Kumar, Mohamed Mostafa. 21
+---------------------+--------------+---------------------------+ +---------------------+--------------+---------------------------+
| 24 kbps EADPCM | "X-G727-24" | None, map dynamically | | 24 kbps EADPCM | "X-G727-24" | None, map dynamically |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| 32 kbps EADPCM | "X-G727-32" | None, map dynamically | | 32 kbps EADPCM | "X-G727-32" | None, map dynamically |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
|n x 64 kbps Clear | "X-CCD" | None, map dynamically | |n x 64 kbps Clear | "X-CCD" | None, map dynamically |
|Channel without CAS | | | |Channel without CAS | | |
|per af-vtoa-78 [7] | | | |per af-vtoa-78 [7] | | |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
|n x 64 kbps Clear | "X-CCD-CAS" | None, map dynamically | |n x 64 kbps Clear | "X-CCD-CAS" | None, map dynamically |
skipping to change at line 1402 skipping to change at line 1358
| 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 | | |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
Rajesh Kumar, Mohamed Mostafa. 23 Rajesh Kumar, Mohamed Mostafa. 22
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| ITU H.261 video | "H261" | 31 (Statically Mapped) | | ITU H.261 video | "H261" | 31 (Statically Mapped) |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| ITU H.263 video | "H263" | 33 (Statically Mapped) | | ITU H.263 video | "H263" | 33 (Statically Mapped) |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| ITU H.263 video |"H263-1998" | None, map dynamically | | ITU H.263 video |"H263-1998" | None, map dynamically |
| 1998 version | | | | 1998 version | | |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
| MPEG 1 system stream| "MP1S" | None, map dynamically | | MPEG 1 system stream| "MP1S" | None, map dynamically |
|---------------------|--------------|---------------------------| |---------------------|--------------|---------------------------|
skipping to change at line 1462 skipping to change at line 1418
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:
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
octets). octets). Since this is always represented in hex, the "0x"
Rajesh Kumar, Mohamed Mostafa. 23
prefix shall not be used.
Rajesh Kumar, Mohamed Mostafa. 24
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,
Q.2630.1). This is a task of these bearer signaling protocols. Q.2630.1). This is a task of these bearer signaling protocols.
However, the following informative statements are made to However, the following informative statements are made to
convey a sense of the interoperability that is a goal of convey a sense of the interoperability that is a goal of
current standardization efforts: current standardization efforts:
- ITU Q.2941.3 and the ATMF each recommend the use of the - ITU Q.2941.3 and the ATMF each recommend the use of the
GIT IE for carrying the eecid (synonymous with bnc-id) GIT IE for carrying the eecid (synonymous with bnc-id)
skipping to change at line 1522 skipping to change at line 1480
5.6.4 The 'silenceSupp' attribute 5.6.4 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>
Rajesh Kumar, Mohamed Mostafa. 25 Rajesh Kumar, Mohamed Mostafa. 24
If any of the parameters in the silenceSupp media attribute line If any of the parameters in the silenceSupp 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
"-". "-".
The <silenceSuppEnable> can take on values of "on" or "off". If it The <silenceSuppEnable> can take on values of "on" or "off". If it
is "on", then silence suppression is enabled. is "on", then silence suppression is enabled.
The <silenceTimer> is a 16-bit field which can be represented in The <silenceTimer> is a 16-bit field which can be represented in
decimal or hex. Each increment (tick) of this timer represents decimal or hex. Each increment (tick) of this timer represents
a millisecond. The maximum value of this timer is between 1 and 3 a millisecond. The maximum value of this timer is between 1 and 3
skipping to change at line 1574 skipping to change at line 1532
| 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)|
+-----------------------+---------------------+ +-----------------------+---------------------+
A hex representation, preceded by a 0x prefix, of <fxnslevel> In addition to the decimal representation of <fxnslevel>, a
is allowed. hex representation, preceded by a "0x" prefix, is also allowed.
5.6.5 The 'ecanf' and 'ecanb' attributes 5.6.5 The 'ecanf' and 'ecanb' attributes
When present, the 'ecanf' and 'ecanb' attributes are used to indicate When present, the 'ecanf' and 'ecanb' attributes are used to indicate
the use or non-use of echo cancellation in the forward the use or non-use of echo cancellation in the forward
and backward directions respectively. See Section and backward directions respectively. See Section
Rajesh Kumar, Mohamed Mostafa. 25
2.3 for a definition of the terms 'forward' and 'backward'. 2.3 for a definition of the terms 'forward' and 'backward'.
Rajesh Kumar, Mohamed Mostafa. 26
The format of the 'ecanf' and 'ecanb' media attribute lines is The format of the 'ecanf' and 'ecanb' media attribute lines is
as follows: as follows:
a=ecanf: <ecanEnable> <ecanType> a=ecanf: <ecanEnable> <ecanType>
a=ecanb: <ecanEnable> <ecanType> a=ecanb: <ecanEnable> <ecanType>
If any of the parameters in the ecanf and ecanb media attribute lines If any of the parameters in the ecanf and ecanb media attribute lines
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
"-". "-".
skipping to change at line 1644 skipping to change at line 1603
etc. 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
Rajesh Kumar, Mohamed Mostafa. 27 Rajesh Kumar, Mohamed Mostafa. 26
(0xFFFE) of inserted loss, is an absurdly 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
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.
5.6.7 The 'profileDesc' attribute 5.6.7 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: <transport> <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>
Here, <transport> and <profile> are identical to their definition, Here, <aal2transport> can have those values of <transport> (Table 1) that
above, for the 'm' line. pertain to AAL2. These are:
AAL2/ATMF
AAL2/ITU
AAL2/custom
AAL2/<corporateName>
AAL2/IEEE:<oui>
The parameter <profile> is identical to its definition for the 'm'
line (Section 5.5.4).
The profile elements (rows in the profile tables of ITU I.366.2 or The profile elements (rows in the profile tables of ITU I.366.2 or
AF-VTOA-0113) are represented as four-tuples following the <profile> AF-VTOA-0113) are represented as four-tuples following the <profile>
parameter in the 'profileDesc' media attribute line. If a member of parameter in the 'profileDesc' media attribute line. If a member of
one of these four-tuples is not specified or is implied, then it is one of these four-tuples is not specified or is implied, then it is
set to "-". set to "-".
The <uuiCodeRange> parameter is represented by D1-D2, where D1 and The <uuiCodeRange> parameter is represented by D1-D2, where D1 and
D2 are decimal integers in the range 0 through 15. D2 are decimal integers in the range 0 through 15.
skipping to change at line 1697 skipping to change at line 1665
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 ms. packetization interval in ms.
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
M and the sequence number interval, see ITU I.366.2 [13]. M and the sequence number interval, see ITU I.366.2 [13].
Rajesh Kumar, Mohamed Mostafa. 27
a=profileDesc:AAL2/custom 100 0-7 PCMG 40 5 0-7 SIDG 1 5 8-15 a=profileDesc:AAL2/custom 100 0-7 PCMG 40 5 0-7 SIDG 1 5 8-15
G726-32 40 10 8-15 SIDG 1 5 G726-32 40 10 8-15 SIDG 1 5
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
Rajesh Kumar, Mohamed Mostafa. 28
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
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. |
skipping to change at line 1761 skipping to change at line 1728
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 ms. The parameters representation of the packetization interval in ms. 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, the
entire 'vsel' media attribute line can be omitted when not needed. entire 'vsel' media attribute line can be omitted when not needed.
For example, For example,
Rajesh Kumar, Mohamed Mostafa. 28
a=vsel:G729 10 10 G726-32 40 10 a=vsel:G729 10 10 G726-32 40 10
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
Rajesh Kumar, Mohamed Mostafa. 29
a=vsel:G729 - - G726-32 - - a=vsel:G729 - - G726-32 - -
The media attribute line The media attribute line
a=vsel:G726-32 40 10 a=vsel:G726-32 40 10
indicates preference for or selection of 32 kbps ADPCM with a packet indicates preference for or selection of 32 kbps ADPCM with a packet
length of 40 octets and a packetization interval of 10 ms. length of 40 octets and a packetization interval of 10 ms.
This media attribute line can be used in the AAL1, AAL2 and This media attribute line can be used in the AAL1, AAL2 and
skipping to change at line 1822 skipping to change at line 1789
<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. 29
For example, For example,
a=dsel:- G726-32 20 5 PCMU 40 5 a=dsel:- G726-32 20 5 PCMU 40 5
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.
Rajesh Kumar, Mohamed Mostafa. 30
This media attribute line can be used in the AAL1, AAL2 and This media attribute line can be used in the AAL1, AAL2 and
AAL5 contexts. The <packetLength> and <packetTime> are not meaningful AAL5 contexts. 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 voiceband data service e.g. row A preferred to row B etc. profile to voiceband data 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
skipping to change at line 1882 skipping to change at line 1849
a=fsel:FXDMOD-3 - - a=fsel:FXDMOD-3 - -
indicates demodulation and remodulation of ITU-T group 3 fax at the indicates demodulation and remodulation of ITU-T group 3 fax at the
gateway. gateway.
a=fsel:PCMU 40 5 G726-32 20 5 a=fsel:PCMU 40 5 G726-32 20 5
indicates a first and second preference of Mu-law PCM and 32 kbps indicates a first and second preference of Mu-law PCM and 32 kbps
ADPCM as the facsimile encoding scheme. The packet length ADPCM as the facsimile encoding scheme. The packet length
Rajesh Kumar, Mohamed Mostafa. 30
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.
This media attribute line can be used in the AAL1, AAL2 and This media attribute line can be used in the AAL1, AAL2 and
AAL5 contexts. The <packetLength> and <packetTime> are not meaningful AAL5 contexts. 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 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
Rajesh Kumar, Mohamed Mostafa. 31
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.
5.6.11 The 'capability' attribute 5.6.11 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].
skipping to change at line 1944 skipping to change at line 1911
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
GFR 1 GFR.1 GFR 1 GFR.1
Rajesh Kumar, Mohamed Mostafa. 31
GFR 2 GRR.2 GFR 2 GRR.2
SBR 1 SBR1 SBR 1 SBR1
SBR 2 SBR2 SBR 2 SBR2
SBR 3 SBR3 SBR 3 SBR3
It is beyond the scope of this specification to examine the It is beyond the scope of this specification to examine the
equivalence of some of the ATMF and ITU definitions. These need to equivalence of some of the ATMF and ITU definitions. These need to
be recognized from the ATMF and ITU source specifications and exploited, be recognized from the ATMF and ITU source specifications and exploited,
as much as possible, to simplify ATM node design. as much as possible, to simplify ATM node design.
When the bearer connection is a single AAL2 CID connection within a When the bearer connection is a single AAL2 CID connection within a
Rajesh Kumar, Mohamed Mostafa. 32
multiplexed AAL2 VC, the 'capability' attribute does not apply. multiplexed AAL2 VC, the 'capability' attribute does not apply.
5.6.12 The 'qosClass' attribute 5.6.12 The 'qosClass' attribute
When present, the 'qosClass' attribute indicates the QoS class When present, the 'qosClass' attribute indicates the QoS class
specified in ITU I.2965.1 [34]. specified in ITU I.2965.1 [34].
The 'qosClass' media attribute line is structured as follows: The 'qosClass' media attribute line is structured as follows:
a=qosClass:<qosClass> a=qosClass:<qosClass>
skipping to change at line 2006 skipping to change at line 1973
24 BCOB-VP (transparent VP service) 24 BCOB-VP (transparent VP service)
5.6.14 The 'stc' attribute 5.6.14 The 'stc' attribute
When present, the 'stc' attribute represents susceptibility When present, the 'stc' attribute represents susceptibility
to clipping. The 'stc' media attribute line is structured as to clipping. The 'stc' media attribute line is structured as
follows: follows:
a=stc:<stc> a=stc:<stc>
Rajesh Kumar, Mohamed Mostafa. 32
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. 33
5.6.15 The 'upcc' attribute 5.6.15 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:
skipping to change at line 2051 skipping to change at line 2017
a=atmQOSfparms: <cdvType><acdv><ccdv><actd><cctd><aclr> a=atmQOSfparms: <cdvType><acdv><ccdv><actd><cctd><aclr>
a=atmQOSbparms: <cdvType><acdv><ccdv><actd><cctd><aclr> a=atmQOSbparms: <cdvType><acdv><ccdv><actd><cctd><aclr>
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 or hex equivalent of microseconds and represented as the decimal equivalent
of 24-bit fields. 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]
and in ITU I.356 [47]. and in ITU I.356 [47].
The CTD parameters, <actd> and <cctd>, refer to the acceptable and The CTD parameters, <actd> and <cctd>, refer to the acceptable and
cumulative CTDs respectively in milliseconds. These are represented as the cumulative CTDs respectively in milliseconds. These are represented as
decimal or hex equivalent of 16-bit fields. These parameters are the decimal equivalents of 16-bit fields. These parameters are
equivalent to the maximum end-to-end transit delay defined in ATMF TM equivalent to the maximum end-to-end transit delay defined in ATMF TM
4.1 specification [6] and Q.2965.2 [35]. 4.1 specification [6] and Q.2965.2 [35].
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 or lost and the number of cells transmitted. It is expressed as the decimal
hex equivalent of an 8-bit field. This field expresses an order of
Rajesh Kumar, Mohamed Mostafa. 33
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 If any of these parameters is not specified, is inapplicable or is
implied, then it is set to "-". implied, then it is set to "-".
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=atmQOSfparms:pp 8125 3455 32000 - 11
Rajesh Kumar, Mohamed Mostafa. 34
a=atmQOSbparms:pp 4675 2155 18000 - 12 a=atmQOSbparms:pp 4675 2155 18000 - 12
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 acceptable maximum peak-to-peak CDV of 2.155 ms, a forward acceptable maximum
cell transfer delay of 32 ms, a backward acceptable maximum cell transfer delay of 32 ms, a backward acceptable maximum
cell transfer delay of 18 ms, an unspecified forward cumulative cell transfer delay of 18 ms, an unspecified forward cumulative
cell transfer delay, an unspecified backward cumulative cell transfer cell transfer delay, an unspecified backward cumulative cell transfer
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
skipping to change at line 2127 skipping to change at line 2093
If any of these parameters in these media attribute lines is not If any 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 "-".
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
Rajesh Kumar, Mohamed Mostafa. 34
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.
Rajesh Kumar, Mohamed Mostafa. 35
The meaning, units and applicability of the remaining parameters The meaning, units and applicability of the remaining parameters
are per the ATMF TM 4.1 specification [6] and are reiterated below: are per the ATMF TM 4.1 specification [6] and are reiterated below:
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
skipping to change at line 2185 skipping to change at line 2152
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:
a=atmFtrfcDesc:0+1 200 100 20 - - - on - a=atmFtrfcDesc:0+1 200 100 20 - - - on -
a=atmFtrfcDesc:0 200 80 15 - - - - off a=atmFtrfcDesc:0 200 80 15 - - - - off
a=atmBtrfcDesc:0+1 200 100 20 - - - on - a=atmBtrfcDesc:0+1 200 100 20 - - - on -
a=atmBtrfcDesc:0 200 80 15 - - - - off a=atmBtrfcDesc:0 200 80 15 - - - - off
Rajesh Kumar, Mohamed Mostafa. 35
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
Rajesh Kumar, Mohamed Mostafa. 36
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
decimal integers, with range as defined in Section 6.
In certain applications (such as SIP-based applications), an SDP In certain applications (such as SIP-based applications), an SDP
descriptor might have both the atmFtrfcDesc and atmBtrfcDesc descriptor might have both the atmFtrfcDesc and atmBtrfcDesc
attributes. In other applications (such as Megaco-based applications), attributes. In other applications (such as Megaco-based applications),
the remote descriptor can have the atmFtrfcDesc attribute the remote descriptor can have the atmFtrfcDesc attribute
while the local descriptor can have the atmBtrfcDesc attribute. while the local descriptor can have the atmBtrfcDesc attribute.
5.6.19 The 'aal2FtrfcDesc' and 'aal2BtrfcDesc' attributes 5.6.19 The 'aal2FtrfcDesc' and 'aal2BtrfcDesc' attributes
It might be meaningful to construct descriptors for traffic It might be meaningful to construct descriptors for traffic
at the AAL2 packet (subcell) level. These can tentatively be at the AAL2 packet (subcell) level. These can tentatively be
skipping to change at line 2241 skipping to change at line 2210
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 If any of these parameters in the 'abrFparms' or 'abrBparms' media
attribute lines is not specified, is inapplicable or is implied, attribute lines is not specified, is inapplicable or is implied,
then it is set to "-". 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. 37 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 2304 skipping to change at line 2273
When present, the 'prtfl' attribute is used to indicate the fill When present, the 'prtfl' attribute is used to indicate the fill
level of cells. When this attribute is absent, then level of cells. When this attribute is absent, then
other means (such as provisionable defaults) are used to determine other means (such as provisionable defaults) are used to determine
the presence and level of partial fill. the presence and level of partial fill.
This attribute indicates the number of non-pad payload This attribute indicates the number of non-pad payload
octets, not including any AAL SAR or convergence sublayer octets. For octets, not including any AAL SAR or convergence sublayer octets. For
example, in some AAL1 applications that use partially filled cells with example, in some AAL1 applications that use partially filled cells with
Rajesh Kumar, Mohamed Mostafa. 38 Rajesh Kumar, Mohamed Mostafa. 37
padding at the end, this attribute indicates the number of leading padding at the end, this attribute indicates the number of leading
payload octets not including any AAL overhead. payload octets not including any AAL overhead.
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
skipping to change at line 2365 skipping to change at line 2334
<localInititiation> flag can be omitted or set to "-". In the <localInititiation> 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 <localInititiation> when this is to be indicated explicitly that the <localInititiation>
flag takes on the values of "on" or "off". An "on" value indicates flag takes on the values of "on" or "off". An "on" value indicates
that the media gateway is responsible for initiating connection set-up that the media gateway is responsible for initiating connection set-up
via bearer signaling (SVC signaling or Q.2630.1 signaling), via bearer signaling (SVC signaling or Q.2630.1 signaling),
an "off" value indicates otherwise. an "off" value indicates otherwise.
Rajesh Kumar, Mohamed Mostafa. 39 Rajesh Kumar, Mohamed Mostafa. 38
5.6.25 The 'structure' attribute 5.6.25 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 (Q.2931)
that can be represented in decimal or hex. It can be omitted or 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 omitted or 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.
5.6.26 The 'sbc' attribute 5.6.26 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,
skipping to change at line 2426 skipping to change at line 2395
backward directions respectively. See section 2.3 for a definition of the backward directions respectively. See section 2.3 for a definition of the
terms 'forward' and 'backward'. The format of these media attribute lines is terms 'forward' and 'backward'. The format of these media attribute lines is
as follows: as follows:
a=fcpsSDUsize: <cpcs> a=fcpsSDUsize: <cpcs>
a=bcpsSDUsize: <cpcs> a=bcpsSDUsize: <cpcs>
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.
Rajesh Kumar, Mohamed Mostafa. 39
The meaning and values of these fields are as follows: The meaning and values of these fields are as follows:
Rajesh Kumar, Mohamed Mostafa. 40
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
In certain applications (such as SIP-based applications), an SDP In certain applications (such as SIP-based applications), an SDP
descriptor might have both the fcpsSDUsize and bcpsSDUsize descriptor might have both the fcpsSDUsize and bcpsSDUsize
attributes. In other applications (such as Megaco-based applications), attributes. In other applications (such as Megaco-based applications),
the remote descriptor can have the fcpsSDUsize attribute the remote descriptor can have the fcpsSDUsize attribute
skipping to change at line 2486 skipping to change at line 2455
The <adt> flag indicates the presence of absence of assured data The <adt> flag indicates the presence of absence of assured data
transfer as defined in I.366.1. The <ted> flag indicates the transfer as defined in I.366.1. The <ted> flag indicates the
presence of absence of transmission error detection as defined presence of absence of transmission error detection as defined
in I.366.1. Each of these flags can take on the values of "on" in I.366.1. Each of these flags can take on the values of "on"
or "off". An "on" value indicates presence of the capability. or "off". An "on" value indicates presence of the capability.
The <fsssar> and <bsssar> fields are 16-bit integers that The <fsssar> and <bsssar> fields are 16-bit integers that
can be represented in decimal or in hex. The meaning and values of can be represented in decimal or in hex. The meaning and values of
the <fsssar> and <bsssar> fields are as follows: the <fsssar> and <bsssar> fields are as follows:
Rajesh Kumar, Mohamed Mostafa. 41 Rajesh Kumar, Mohamed Mostafa. 40
Field Meaning Values Field Meaning Values
<fsssar> Maximum SSSAR-SDU size 1- 65,535 <fsssar> Maximum SSSAR-SDU size 1- 65,535
forward direction forward direction
<bsssar> Maximum SSSAR-SDU size 1- 65,535 <bsssar> Maximum SSSAR-SDU size 1- 65,535
backward direction backward direction
In certain applications (such as SIP-based applications), an SDP In certain applications (such as SIP-based applications), an SDP
descriptor might have an 'aal2sscs3661' media attribute line descriptor might have an 'aal2sscs3661' media attribute line
skipping to change at line 2546 skipping to change at line 2515
The <cas> flag indicates whether the transport of Channel The <cas> flag indicates whether the transport of Channel
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
Rajesh Kumar, Mohamed Mostafa. 41
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
Rajesh Kumar, Mohamed Mostafa. 42
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"
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
skipping to change at line 2606 skipping to change at line 2575
a=aalApp: <aalApp> a=aalApp: <aalApp>
The <aalApp> field can take on the string values listed The <aalApp> field can take on the string values listed
below, along with their meaning. Note that most applications which are below, along with their meaning. Note that most applications which are
specified to run on AAL5 can also run on one or more of the AAL2 specified to run on AAL5 can also run on one or more of the AAL2
SSCS variants (TED and ADT) specified in I.366.1. SSCS variants (TED and ADT) specified in I.366.1.
This list is not exhaustive. Other values are possible. If used, these need This list is not exhaustive. Other values are possible. If used, these need
to be defined consistently across an application. to be defined consistently across an application.
Rajesh Kumar, Mohamed Mostafa. 43 Rajesh Kumar, Mohamed Mostafa. 42
<aalApp> Meaning <aalApp> Meaning
"itu_h323c" Annex C of H.323 which specifies direct "itu_h323c" Annex C of H.323 which specifies direct
RTP on AAL5 [45]. RTP on AAL5 [45].
"af83" af-vtoa-0083.001, which specifies "af83" af-vtoa-0083.001, which specifies
variable size AAL5 PDUs with PCM voice variable size AAL5 PDUs with PCM voice
and a null SSCS [46]. and a null SSCS [46].
"assuredSSCOP" SSCOP as defined in ITU Q.2110 [43], "assuredSSCOP" SSCOP as defined in ITU Q.2110 [43],
skipping to change at line 2667 skipping to change at line 2636
specification [5]. It is possible that the values of this field will specification [5]. It is possible that the values of this field will
be defined later by the ATMF and/or ITU. Currently, all values are be defined later by the ATMF and/or ITU. Currently, all values are
reserved with the exception of 0, which indicates a 'Network Join reserved with the exception of 0, which indicates a 'Network Join
without Root Notification'. without Root Notification'.
The <lsn> (leaf sequence number) is a 32-bit field expressed as a The <lsn> (leaf sequence number) is a 32-bit field expressed as a
decimal or hex integer. Per the UNI 4.0 signaling specification [5], it decimal or hex integer. Per the UNI 4.0 signaling specification [5], it
is used by a joining leaf to associate messages and responses during is used by a joining leaf to associate messages and responses during
LIJ (leaf initiated join) procedures. LIJ (leaf initiated join) procedures.
Rajesh Kumar, Mohamed Mostafa. 43
Each of these fields can be set to a "-" when the intention Each of these fields can be set to a "-" when the intention
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is to not specify them in an SDP descriptor. is to not specify them in an SDP descriptor.
5.6.33 The 'anycast' attribute 5.6.33 The 'anycast' attribute
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>
skipping to change at line 2728 skipping to change at line 2696
respectively. respectively.
The <cacheTimer> indicates the period of inactivity following which The <cacheTimer> indicates the period of inactivity following which
the SVC is to be released by sending an SVC release message into the SVC is to be released by sending an SVC release message into
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
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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.
Rajesh Kumar, Mohamed Mostafa. 45
The <cacheTimer> can be set to "-" if it is inapplicable or implied. The <cacheTimer> can be set to "-" if it is inapplicable or implied.
5.6.35 Specification of Higher-layer attributes 5.6.35 Specification of Higher-layer attributes
This conventions in this ATM SDP document are limited to the ATM and adaptation This conventions in this ATM SDP document are limited to the ATM and adaptation
layers. Parameters associated with layers higher than the ATM adaptation layers. Parameters associated with layers higher than the ATM adaptation
layer are addressed only if these are tightly coupled to the ATM or layer are addressed only if these are tightly coupled to the ATM or
adaptation layers. adaptation layers.
ATM signaling standards provide 'escape mechanisms' to ATM signaling standards provide 'escape mechanisms' to
skipping to change at line 2785 skipping to change at line 2753
The <rtcpPortNum> and <rtcpIPaddr> subparameters indicate the port number The <rtcpPortNum> and <rtcpIPaddr> subparameters indicate the port number
and IP address on which the media gateway is prepared to receive RTCP packets. and IP address on which the media gateway is prepared to receive RTCP packets.
Any of the subparameters on these lines can be set to "-" if they are known by Any of the subparameters on these lines can be set to "-" if they are known by
other means. other means.
The range and format of the <rtcpPortNum> and <rtcpIPaddr> subparameters is per The range and format of the <rtcpPortNum> and <rtcpIPaddr> subparameters is per
[1]. The <rtcpPortNum> is a decimal number between 1024 and 65535. It is an odd [1]. The <rtcpPortNum> is a decimal number between 1024 and 65535. It is an odd
number. If an even number in this range is specified, the next odd number is number. If an even number in this range is specified, the next odd number is
used. The <rtcpIPaddr> is expressed in the usual dotted decimal IP address used. The <rtcpIPaddr> is expressed in the usual dotted decimal IP address
representation, from 0.0.0.0 to 255.255.255.255, resulting in an alphanumeric representation, from 0.0.0.0 to 255.255.255.255.
string of 7 to 15 characters.
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5.6.37 Chaining SDP descriptors 5.6.37 Chaining SDP descriptors
The start of an SDP descriptor is marked by a 'v' line. In some The start of an SDP descriptor is marked by a 'v' line. In some
applications, consecutive SDP descriptions are alternative descriptions applications, consecutive SDP descriptions are alternative descriptions
of the same session. In others, these describe different layers of the of the same session. In others, these describe different layers of the
same connection (e.g. IP, ATM, frame relay). This is useful when these same connection (e.g. IP, ATM, frame relay). This is useful when these
connectivity at these layers are established at the same time e.g. an connectivity at these layers are established at the same time e.g. an
IP-based session over an ATM SVC. To distinguish between the IP-based session over an ATM SVC. To distinguish between the
alternation and concatenation of SDP descriptions, a 'chain' attribute alternation and concatenation of SDP descriptions, a 'chain' attribute
skipping to change at line 2817 skipping to change at line 2784
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>
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.
5.6.38 Use of the eecid media attribute in call establishment procedures 5.6.38 Use of the eecid media attribute in call establishment procedures
This informative section supplements the definition of the eecid This informative section supplements the definition of the eecid
attribute (Section 5.6.2) by describing example procedures for its use. attribute (Section 5.6.2) by describing example procedures for its use.
skipping to change at line 2852 skipping to change at line 2819
| | | |
+------------+ (ATM Network) +------------+ +------------+ (ATM Network) +------------+
|Originating |------------------|Terminating | |Originating |------------------|Terminating |
|Media | Bearer Setup |Media | |Media | Bearer Setup |Media |
|Gateway | Protocol |Gateway | |Gateway | Protocol |Gateway |
+------------+ +------------+ +------------+ +------------+
In the diagram above, the originating media gateway originates the service- In the diagram above, the originating media gateway originates the service-
level call. The terminating media gateway terminates it. In the forward call level call. The terminating media gateway terminates it. In the forward call
Rajesh Kumar, Mohamed Mostafa. 47 Rajesh Kumar, Mohamed Mostafa. 46
model, the originating media gateway initiates bearer connection set-up. In the model, the originating media gateway initiates bearer connection set-up. In the
backward call model, the terminating gateway initiates bearer connection set- backward call model, the terminating gateway initiates bearer connection set-
up. up.
Example use of the Backward Call Model: Example use of the Backward Call 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).
skipping to change at line 2908 skipping to change at line 2875
m=audio $ - - m=audio $ - -
a=bearerType:SVC on a=bearerType:SVC on
The 'bearerType' attribute indicates that an SVC is to be used and The 'bearerType' attribute indicates that an SVC is to be used and
that the <localInititiation> flag is on i.e. the SVC is to be set up that the <localInititiation> flag is on i.e. the SVC is to be set up
by the TMG. by the TMG.
(5) The TMG acknowledges the control message from the TMGC. It returns (5) The TMG acknowledges the control message from the TMGC. It returns
the following SDP descriptor with the acknowledge: the following SDP descriptor with the acknowledge:
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v=0 v=0
o=- 2873397498 0 ATM NSAP o=- 2873397498 0 ATM NSAP
47.0091.8100.0000.0040.2A74.EB03.0020.4421.2A04.00 47.0091.8100.0000.0040.2A74.EB03.0020.4421.2A04.00
s=- s=-
c=ATM NSAP c=ATM NSAP
47.0091.8100.0000.0040.2A74.EB03.0020.4421.2A04.00 47.0091.8100.0000.0040.2A74.EB03.0020.4421.2A04.00
t=0 0 t=0 0
m=audio $ AAL2/ITU 8 m=audio $ AAL2/ITU 8
The NSAP address information provided in this descriptor is not needed. The NSAP address information provided in this descriptor is not needed.
skipping to change at line 2969 skipping to change at line 2936
NSAP address provided by the OMG. NSAP address provided 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. descriptor contains the NSAP address of the OMG.
(5) The TMG acknowledges the control message from the TMGC. Along with (5) The TMG acknowledges the control message from the TMGC. Along with
the acknowledgement, it provides an SDP descriptor with a locally the acknowledgement, it provides an SDP descriptor with a locally
assigned eecid. assigned eecid.
Rajesh Kumar, Mohamed Mostafa. 49 Rajesh Kumar, Mohamed Mostafa. 48
v=0 v=0
o=- 2873397714 0 ATM NSAP o=- 2873397714 0 ATM NSAP
47.0091.8100.0000.0040.2A74.EB03.0020.4421.2A04.00 47.0091.8100.0000.0040.2A74.EB03.0020.4421.2A04.00
s=- s=-
c=ATM NSAP c=ATM NSAP
47.0091.8100.0000.0040.2A74.EB03.0020.4421.2A04.00 47.0091.8100.0000.0040.2A74.EB03.0020.4421.2A04.00
t=0 0 t=0 0
m=audio $ AAL2/ITU 8 m=audio $ AAL2/ITU 8
a=eecid:B3D58E32 a=eecid:B3D58E32
skipping to change at line 3025 skipping to change at line 2992
(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. 49
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.
Rajesh Kumar, Mohamed Mostafa. 50
PARAMETER MEANING REPRESENTATION PARAMETER MEANING REPRESENTATION
<username> User name Constant "-" <username> User name Constant "-"
<sessionID> Session ID Up to 34 alphanumeric <sessionID> Session ID Up to 32 decimal or
characters. hex digits
<version> Version of 10 decimal or 8 hex <version> Version of "0" or 10 decimal digits
SDP descriptor digits SDP descriptor
<networkType> Network type Constant "ATM" <networkType> Network type Constant "ATM"
<ATMaddressType> ATM address type String values: <ATMaddressType> ATM address type String values:
"NSAP", "E164", "GWID", "NSAP", "E164", "GWID",
"ALIAS" "ALIAS"
<ATMaddress> ATM address "NSAP": 40 hex digits, <ATMaddress> ATM address "NSAP": 40 hex digits, dotted
optionally dotted
"E164": up to 15 decimal digits "E164": up to 15 decimal digits
"GWID": up to 32 characters "GWID": up to 32 characters
"ALIAS": up to 32 characters "ALIAS": up to 32 characters
<sessionName> Session name Constant "-" <sessionName> Session name Constant "-"
<startTime> Session start 10 decimal or 8 hex <startTime> Session start "0" or 10 decimal digits
time digits time
<stopTime> Session stop Constant "0" <stopTime> Session stop Constant "0"
time time
<vcci> Virtual Circuit Decimal or hex equivalent <vcci> Virtual Circuit Decimal or hex equivalent
Connection of 16 bits Connection of 16 bits
Identifier Identifier
<ex_vcci> Explicit "VCCI-" prefixed to <vcci> <ex_vcci> Explicit "VCCI-" prefixed to <vcci>
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>
<portId> Port ID Up to 34 alphanumeric <portId> Port ID Hex number of up to 32 digits
characters.
<ex_portId> Explicit "PORT-" prefixed to <portId> <ex_portId> Explicit "PORT-" prefixed to <portId>
representation representation
of <portId> of <portId>
Rajesh Kumar, Mohamed Mostafa. 50
<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
<ex_vpi> Explicit "VPI-" prefixed to <vpi> <ex_vpi> Explicit "VPI-" prefixed to <vpi>
representation representation
of <vpi> of <vpi>
Rajesh Kumar, Mohamed Mostafa. 51
<vci> Virtual Circuit Decimal or hex equivalent <vci> Virtual Circuit Decimal or hex equivalent
Identifier of 16 bits Identifier of 16 bits
<ex_vci> Explicit "VCI-" prefixed to <vci> <ex_vci> Explicit "VCI-" prefixed to <vci>
representation representation
of <vci> of <vci>
<vpci> Virtual Path Decimal or hex equivalent <vpci> Virtual Path Decimal or hex equivalent
Connection of 16 bits Connection of 16 bits
Identifier Identifier
skipping to change at line 3120 skipping to change at line 3085
<cid> Channel Decimal or hex equivalent <cid> Channel Decimal or hex equivalent
Identifier of 8 bits Identifier of 8 bits
<ex_cid> Explicit "CID-" prefixed to <cid> <ex_cid> Explicit "CID-" prefixed to <cid>
representation representation
of <cid> of <cid>
<payloadType> Payload Decimal integer 0-127 <payloadType> Payload Decimal integer 0-127
Type Type
<transport> Transport String 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
<aalType> AAL type String values: <aalType> AAL type String values:
"AAL1","AAL1_SDT","AAL1_UDT", "AAL1","AAL1_SDT","AAL1_UDT",
skipping to change at line 3147 skipping to change at line 3112
<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" "Sampled Noise"
<fxnslevel> Fixed Noise Decimal or hex representation <fxnslevel> Fixed Noise Decimal or hex representation
Rajesh Kumar, Mohamed Mostafa. 51
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:
Rajesh Kumar, Mohamed Mostafa. 52
Cancellation "G165", "G168" Cancellation "G165", "G168"
<gcEnable> Enable Gain String values: <gcEnable> Enable Gain String values:
Control "on", "off" Control "on", "off"
<gcLvl> Level of inserted Decimal or hex equivalent <gcLvl> Level of inserted Decimal or hex equivalent
Loss of 16-bit field Loss of 16-bit field
<aal2transport> AAL2 transport Values listed in Table 1
that begin with the string
"AAL2"
<uuiCodeRange> UUI code range Decimal integer 0-15 <uuiCodeRange> UUI code range Decimal integer 0-15
<encodingName> Encoding name String values: <encodingName> Encoding name String values:
"PCMG", "SIDG", "SID729", "PCMG", "SIDG", "SID729",
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 1-500 <packetTime> Packetization Decimal integer 1-255
Interval Interval
<fxIncl> Facsimile included String values: "on", "off" <fxIncl> Facsimile included String values: "on", "off"
<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"
<atc> ATM transfer String values: <atc> ATM transfer String values:
capability "DBR","SBR","ABT/IT","ABT/DT", capability "DBR","SBR","ABT/IT","ABT/DT",
defined by the "ABR" defined by the "ABR"
ITU ITU
<subtype> <asc>/<atc> Decimal integer <subtype> <asc>/<atc> Decimal integer 1-10
subtype subtype
<qosClass> QoS Class Decimal integer 0-5 <qosClass> QoS Class Decimal integer 0-5
<bcob> Broadband Bearer Decimal or hex representation <bcob> Broadband Bearer Decimal or hex representation
Class of 5-bit field Class of 5-bit field
<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
<cdvType> CDV type String values: <cdvType> CDV type String values:
"PP", "2P" "PP", "2P"
<acdv> Acceptable CDV Integer or hex equivalent <acdv> Acceptable CDV Decimal equivalent
Rajesh Kumar, Mohamed Mostafa. 52
of 24-bit field of 24-bit field
<ccdv> Cumulative CDV Integer or hex equivalent <ccdv> Cumulative CDV Decimal equivalent
of 24-bit field of 24-bit field
<actd> Acceptable CTD Integer or hex equivalent <actd> Acceptable CTD Decimal equivalent
of 16-bit field of 16-bit field
<cctd> Cumulative CTD Integer or hex equivalent <cctd> Cumulative CTD Decimal equivalent
of 16-bit field of 16-bit field
Rajesh Kumar, Mohamed Mostafa. 53 <aclr> Acceptable Decimal equivalent
<aclr> Acceptable Integer or hex equivalent
Cell Loss Ratio of 8-bit field Cell Loss Ratio of 8-bit field
<clpLvl> CLP level String values: <clpLvl> CLP level String values:
"0", "0+1" "0", "0+1"
<pcr> Peak Cells/second <pcr> Peak Decimal integer, 1-100,000
Cell Rate Cell Rate
<scr> Sustained Cells/second <scr> Sustained Decimal integer, 1-100,000
Cell Rate Cell Rate
<mbs> Maximum Cells <mbs> Maximum Decimal integer, 1-10,000
Burst Size Burst Size
<cdvt> CDVT Decimal integer or <cdvt> CDVT Decimal equivalent of 24-bit
fraction, range determined field.
by application.
<mcr> Minimum Cells/second <mcr> Minimum Decimal integer, 1-100,000
Cell Rate Cell Rate
<mfs> Maximum Cells <mfs> Maximum Decimal integer, 1-10,000
Frame Size Frame Size
<fd> Frame Discard String Values: <fd> Frame Discard String Values:
Allowed "on", "off" Allowed "on", "off"
<te> CLP tagging String Values: <te> CLP tagging String Values:
Enabled "on", "off" "on", "off"
<nrm> NRM Decimal/hex equivalent <nrm> NRM Decimal/hex equivalent
of 3 bit field of 3 bit field
<trm> TRM - ditto- <trm> TRM - ditto-
<cdf> CDF -ditto- <cdf> CDF -ditto-
<adtf> ADTF Decimal/Hex equivalent <adtf> ADTF Decimal/Hex equivalent
of 10 bit field of 10 bit field
skipping to change at line 3272 skipping to change at line 3239
Method "NULL", "SRTS", Method "NULL", "SRTS",
"ADAPTIVE" "ADAPTIVE"
<fecEnable> Forward Error String values: <fecEnable> Forward Error String values:
Correction Enable "NULL", "LOSS_SENSITIVE" Correction Enable "NULL", "LOSS_SENSITIVE"
"DELAY_SENSITIVE" "DELAY_SENSITIVE"
<partialFill> Partial Fill Decimal integer 1-48 <partialFill> Partial Fill Decimal integer 1-48
or hex equivalent or hex equivalent
Rajesh Kumar, Mohamed Mostafa. 53
<bearerType> Bearer Type String Values: <bearerType> Bearer Type String Values:
"PVC", "SVC", "CID" "PVC", "SVC", "CID"
<localInititiation> Local Initiation String values:
"on", "off"
<structureEnable> Structure Present String values: <structureEnable> Structure Present String values:
"on", "off" "on", "off"
<blksz> Block Size Decimal or hexadecimal <blksz> Block Size Decimal or hexadecimal
equivalent of 16 bits equivalent of 16 bits
Rajesh Kumar, Mohamed Mostafa. 54
<sbc> Subchannel Count T1: Decimal integer 1-24 <sbc> Subchannel Count T1: Decimal integer 1-24
or hex equivalent or hex equivalent
E1: Decimal integer 1-31 E1: Decimal integer 1-31
or hex equivalent or hex equivalent
<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 AAL2: 45 or 64, decimal
or hex representation
<cidCount> Number of Decimal integer 1-255 <cidCount> Number of Decimal integer 1-255
subcell channels or hex equivalent subcell channels or hex equivalent
<timerCU> Timer, combined use Integer decimal; range <timerCU> Timer, combined use Integer decimal; range
determined by application determined by application.
Use decimal equivalent of
32 bits.
<adt> Assured Data String values: <adt> Assured Data String values:
Transfer Enable "on", "off" Transfer Enable "on", "off"
<ted> Transmission Error String values: <ted> Transmission Error String values:
Detection Enable "on", "off" Detection Enable "on", "off"
<fsssar> Maximum SSSAR-SDU Decimal or hex <fsssar> Maximum SSSAR-SDU Decimal or hex
size, forward equivalent of 16-bit size, forward equivalent of 16-bit
direction field direction field
skipping to change at line 3327 skipping to change at line 3300
<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"
Rajesh Kumar, Mohamed Mostafa. 54
<dtmf> Enable DTMF transport String values: <dtmf> Enable DTMF transport String values:
via Type 3 packets "on", "off" via Type 3 packets "on", "off"
<mfall> Enable MF transport String values: <mfall> Enable MF transport String values:
via Type 3 packets "on", "off" via Type 3 packets "on", "off"
<mfr1> Enable MF (R1) String values: <mfr1> Enable MF (R1) String values:
transport via "on", "off" transport via "on", "off"
Type 3 packets Type 3 packets
<mfr2> Enable MF (R2) String values: <mfr2> Enable MF (R2) String values:
transport via "on", "off" transport via "on", "off"
Type 3 packets Type 3 packets
<PCMencoding> PCM encoding String values: <PCMencoding> PCM encoding String values:
"PCMA", "PCMU" "PCMA", "PCMU"
Rajesh Kumar, Mohamed Mostafa. 55
<fmaxFrame> Maximum length of a Decimal or hex <fmaxFrame> Maximum length of a Decimal or hex
frame mode data unit, equivalent of frame mode data unit, equivalent of
forward direction 16-bit field forward direction 16-bit field
<bmaxFrame> Maximum length of a -ditto- <bmaxFrame> Maximum length of a -ditto-
frame mode data unit, frame mode data unit,
backward direction backward direction
<aalApp> Application specification String values: <aalApp> Application specification String values:
"itu_h323c","af83", "itu_h323c","af83",
skipping to change at line 3371 skipping to change at line 3344
"FRF5", "FRF8", "FRF5", "FRF8",
"itu_h2221" "itu_h2221"
<sci> Screening Indication Decimal or hex <sci> Screening Indication Decimal or hex
equivalent of 4 bits. equivalent of 4 bits.
<lsn> Leaf Sequence Number Decimal or hex <lsn> Leaf Sequence Number Decimal or hex
equivalent of 32 bits. equivalent of 32 bits.
<cdStd> Coding standard for the Decimal or hex <cdStd> Coding standard for the Decimal or hex
connection scope selection equivalent of connection scope equivalent of
IE 2 bits selection IE 2 bits
Definition: UNI 4.0 [5] Definition: UNI 4.0 [5]
<conScpTyp> Type of connection scope Decimal or hex <conScpTyp> Type of connection scope Decimal or hex
Definition: UNI 4.0 [5] equivalent of 4 bits Definition: UNI 4.0 [5] equivalent of 4 bits
<conScpSel> Connection scope selection Decimal or hex equivalent <conScpSel> Connection scope selection Decimal or hex equivalent
Definition: UNI 4.0 [5] of 8 bits Definition: UNI 4.0 [5] of 8 bits
<cacheEnable> Enable SVC caching String values: "on", "off" <cacheEnable> Enable SVC caching String values: "on", "off"
<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
<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 applications 65,535. H.323 Annex C applications 65,535.
Preferred: Odd number in Preferred: Odd number in
Rajesh Kumar, Mohamed Mostafa. 55
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
<chainPointer> Chain pointer String values: "next", <chainPointer> Chain pointer String values: "NEXT",
"previous", "NULL" "PREVIOUS", "NULL"
Rajesh Kumar, Mohamed Mostafa. 56
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 3446 skipping to change at line 3418
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 5 0-7 SIDG 1 a=profileDesc:AAL2/custom 100 0-7 PCMG 40 5 0-7 SIDG 1
5 8-15 G726-32 40 10 8-15 SIDG 1 5 5 8-15 G726-32 40 10 8-15 SIDG 1 5
a=vsel:G726-32 40 10 a=vsel:G726-32 40 10
a=dsel:off PCMU - - a=dsel:off PCMU - -
a=fsel:G726-32 40 10 a=fsel:G726-32 40 10
Rajesh Kumar, Mohamed Mostafa. 57
An example of an SDP session descriptor for an AAL5 switched virtual circuit 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
Rajesh Kumar, Mohamed Mostafa. 56
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=atmFtrfcDesc:0+1 7816 - - - - - off -
a=atmBtrfcDesc:0+1 0 - - - - - on - a=atmBtrfcDesc:0+1 0 - - - - - on -
a=fcpsSDUsize:20680 a=fcpsSDUsize:20680
skipping to change at line 3493 skipping to change at line 3465
The following encoding names in Table 2 can refer to data as well The following encoding names in Table 2 can refer to data as well
as audio media: X-CCD and X-CCD-CAS in Table 2. as audio media: X-CCD and X-CCD-CAS in Table 2.
The following encoding names in Table 2 refer to data media: The following encoding names in Table 2 refer to data media:
X-FXDMOD-3 in Table 2. X-FXDMOD-3 in Table 2.
In the AAL1 context, X-CCD and X-CCD-CAS can be represented as In the AAL1 context, X-CCD and X-CCD-CAS can be represented as
"audio" codecs that are dynamically mapped into payload types. This "audio" codecs that are dynamically mapped into payload types. This
is done through the 'atmmap' attribute, as described earlier. For is done through the 'atmmap' attribute, as described earlier. For
example: example:
m=audio 27 AAL1/AVP 98 m=audio VCCI-27 AAL1/AVP 98
a=atmmap:98 X-CCD a=atmmap:98 X-CCD
implies that AAL1 VCCI=27 is used for n x 64 transmission. implies that AAL1 VCCI=27 is used for n x 64 transmission.
Currently, AAL1 in unsuitable for transmitting demodulated facsimile Currently, AAL1 in unsuitable for transmitting demodulated facsimile
because it lacks the bearer plane mechanisms (equivalent to AAL2 because it lacks the bearer plane mechanisms (equivalent to AAL2
type 3 messages) for transmitting control information. type 3 messages) for transmitting control information.
In the AAL2 context, these "codecs" can be assigned profile types and In the AAL2 context, these "codecs" can be assigned profile types and
numbers. Even though it is not possible to construct numbers. Even though it is not possible to construct
profile tables as described in ITU I.366.2 for these "codecs", it profile tables as described in ITU I.366.2 for these "codecs", it
is preferable to adopt the common AAL2 profile convention in their is preferable to adopt the common AAL2 profile convention in their
case. An example AAL2 profile mapping for these could be as follows: case. An example AAL2 profile mapping for these could be as follows:
Rajesh Kumar, Mohamed Mostafa. 58
PROFILE TYPE PROFILE NUMBER "CODEC" (ONLY ONE) PROFILE TYPE PROFILE NUMBER "CODEC" (ONLY ONE)
"custom" 200 X-CCD "custom" 200 X-CCD
"custom" 201 X-FXDMOD-3 "custom" 201 X-FXDMOD-3
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.
Rajesh Kumar, Mohamed Mostafa. 57
Currently, there is no definition of n x 64 trunking with CAS for AAL2. Currently, there is no definition of n x 64 trunking with CAS for AAL2.
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
implies a 384 kbps n x 64 circuit using AAL2 adaptation. implies a 384 kbps n x 64 circuit using AAL2 adaptation.
In the case of fax demodulation and remodulation (ITU I.366.2), In the case of fax demodulation and remodulation (ITU I.366.2),
parameters such as information type, image data size and control parameters such as information type, image data size and control
skipping to change at line 3557 skipping to change at line 3530
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
configured shared secrets or the use of a certificate authority. configured shared secrets or the use of a certificate authority.
10. ATM SDP Grammar
This appendix provides an Augmented BNF (ABNF) grammar for the ATM
conventions for SDP. ABNF is defined in rfc2234. This is not a complete ABNF
description of SDP. Readers are referred to [1] for an ABNF description
of the SDP base line protocol, and to rfc2848, rfc2543, rfc2045 and rfc2326
for application-specific conventions for SDP use.
; Constant definitions
safe = alpha-numeric / "'" / "-" / "." / "/" / ":" / "?" / DQUOTE / "#" /
"$" / "&" / "*" / ";" / "=" / "@" / "[" / "]" / "^" / "_" / "`" / "{" /
"|" / "}" / "+" / "~"
DQUOTE = %x22 ; double quote
alpha-numeric = ALPHA / DIGIT
ALPHA = "a" / "b" / "c" / "d" / "e" / "f" / "g" / "h" / "i" / "j" / "k" /
"l" / "m" / "n" / "o" / "p" / "q" / "r" / "s" / "t" / "u" / "v" /
"w" / "x" / "y" / "z" /
"A" / "B" / "C" / "D" / "E" / "F" / "G" / "H" / "I" / "J" / "K" /
Rajesh Kumar, Mohamed Mostafa. 58
"L" / "M" / "N" / "O" / "P" / "Q" / "R" / "S" / "T" / "U" / "V" /
"W" / "X" / "Y" / "Z"
DIGIT = "0" / POS-DIGIT
POS-DIGIT = "1" / "2" / "3" / "4" / "5" / "6" / "7" / "8" / "9"
hex-prefix = "0" ("x" / "X")
HEXDIG = DIGIT / "a" / "b" / "c" / "d" / "e" / "f" /
"A" / "B" / "C" / "D" / "E" / "F"
space = %d32
EOL = (CR / LF / CRLF) ; as per Megaco RFC
CR = %d13
LF = %d10
decimal-uchar = DIGIT
/ POS-DIGIT DIGIT
/ ("1" 2*(DIGIT))
/ ("2" ("0"/"1"/"2"/"3"/"4") DIGIT)
/ ("2" "5" ("0"/"1"/"2"/"3"/"4"/"5"))
generic-U8 = (hex-prefix hex-U8) / decimal-uchar
generic-U12 = (hex-prefix hex-U12) / 1*4 (DIGIT)
generic-U16 = (hex-prefix hex-U16) / 1*5(DIGIT)
generic-U32 = (hex-prefix hex-U32) / 1*10(DIGIT)
hex-U8 = 1*2(HEXDIG)
hex-U12 = 1*3(HEXDIG)
hex-U16 = 1*4(HEXDIG)
hex-U32 = 1*8(HEXDIG)
generic-U8-or-null = generic-U8 / "-"
generic-U12-or-null = generic-U12 / "-"
generic-U16-or-null = generic-U16 / "-"
generic-U32-or-null = generic-U32 / "-"
decimal-U8-or-null = decimal-uchar / "-"
decimal-U12-or-null = 1*4(DIGIT) / "-"
decimal-U16-or-null = 1*5(DIGIT) / "-"
decimal-U32-or-null = 1*10(DIGIT) / "-"
on-off-or-null = "on" / "off" / "-"
; ABNF definition of SDP with ATM conventions
SDP-infoset = 1*(announcement)announcement = proto-version origin-field
session-name-field
information-field uri-field email-fields phone-fields connection-field
bandwidth-fields time-fields key-field attribute-fields media-descriptions
proto-version = ["v=" 1*4(DIGIT) EOL] ; use "v=0" for ATM SDP
origin-field = ["o=" username space sess-id space sess-version space
net-type-addr EOL]
username = 1* safe ; for ATM use "-"
sess-id = (1*32 DIGIT) / (hex-prefix 1*32 HEXDIG)
sess-version = (1*10 DIGIT) / (hex-prefix 1*8 HEXDIG)
net-type-addr= ip-net-type-addr/ atm-net-type-addr/ tn-net-type-addr
; ip-net-type-addr per rfc2327
; tn-net-type-addr per rfc2848
Rajesh Kumar, Mohamed Mostafa. 59
; ATM address definition
atm-net-type-addr= "ATM" space atm-type-addr
atm-type-addr = atm-nsap-addr / atm-e164-addr / atm-alias-addr /
"-" space "-" /"$" space "$"
atm-nsap-addr = "NSAP" space (nsap-addr / "-" / "$")
atm-e164-addr = "E164" space (e164-addr / "-" / "$")
atm-alias-addr = ("GWID" / "ALIAS") space (alias-addr / "-" / "$")
nsap-addr = 2(HEXDIG) "." 9(4(HEXDIG) ".") 2(HEXDIG)
e164-addr = 1*15 (DIGIT)
alias-addr = 1*32(alpha-numeric / "-" / "." / "_")
session-name-field = ["s=" text EOL] ; for ATM use "s=-"
text = byte-string
byte-string = 1*(byte-string-char) ; definition per rfc2327
byte-string-char = %x01-09/ %x0B/ %x0C/ %x0E-FF ; all ASCII except NUL, CR & LF
; Definitions of information-field, uri-field, email-fields,
; phone-fields per rfc2327. These fields are omitted in
; ATM SDP descriptions. If received, they are ignored in the ATM context
connection-field = ["c=" c-net-type-addr] ; required, not optional, in ATM
c-net-type-addr = c-ip-net-type-addr / atm-net-type-addr / tn-net-type-addr
; c-ip-net-type-addr per rfc2327
; atm-net-type-addr defined above
; tn-net-type-addr per rfc2848
bandwidth-fields = *("b=" bwtype ":" bandwidth EOL)
bwtype = 1*(alpha-numeric)
bandwidth = 1*(DIGIT)
time-fields = *( "t=" start-time space stop-time *(EOL repeat-fields) EOL)
[zone-adjustments EOL]
start-time = time / "0"
stop-time = time / "0" ; always "0" in ATM
time = POS-DIGIT 9*(DIGIT) ; same as rfc2327
; repeat-fields and zone-adjustments per rfc2327, not used in ATM
; Definition of optional key-field per rfc2327
;
attribute-fields = *("a=" attribute EOL)
; SDP descriptors for ATM do not have session-level media attribute lines
; If these are provided, they should be ignored.
media-descriptions = *(media-description)
media-description = media-field information-field *(connection-field)
bandwidth-fields key-field attribute-fields
Rajesh Kumar, Mohamed Mostafa. 60
; Definitions of information-field per rfc2327. This fields are omitted in
; ATM SDP descriptions. If received, they are ignored in the ATM context
;
; In ATM, the connection-field is used in media-description to indicate
; the IP address associated with the RTCP control protocol in H.323.C
; applications. In this case, the connection field is per the rfc2327
; definition for IP v4-based connections. Otherwise, it is not used in
; media-description. If received as part of media-description,
; it is ignored.
;
; Definition of optional bandwidth-fields as above.
: Definition of optional key-field as in rfc2327
media-field = rfc2327-media-field / rfc2848-media-field / atm-media-field
; rfc2327-media-field and rfc2848-media-field defined in those rfc's
atm-media-field = "m=" media space vcId space transport-fmts EOL
; superset of rfc2327 definition
media = "audio" / "video" / "data" / "application" / "control" /
1*(alpha-numeric)
vcId = "$" / ex-vcci / (ex-vcci "/" ex-cid) /
(atm-type-addr-m "/" ex-vcci) /
(atm-type-addr-m "/" ex-vcci "/" ex-cid) /
(ex-bcg "/" ex-vcci) / (ex-bcg "/" ex-vcci "/" ex-cid)
(ex-portid "/" ex-vpi "/" ex-vci) /
(ex-portid "/" ex-vpi "/" ex-vci "/" ex-cid) /
(ex-bcg "/" ex-vpi "/" ex-vci) /
(ex-bcg "/" ex-vpi "/" ex-vci "/" ex-cid) /
(ex-vpci "/" ex-vci) /
(ex-vpci "/" ex-vci "/" ex-cid) /
(atm-type-addr-m "/" ex-vpci "/" ex-vci) /
(atm-type-addr-m "/" ex-vpci "/" ex-vci "/" ex-cid)
atm-type-addr-m = atm-nsap-addr-m / atm-e164-addr-m / atm-alias-addr-m
atm-nsap-addr-m = ["NSAP-"] (nsap-addr / "$")
atm-e164-addr-m = ["E164-"] (e164-addr / "$")
atm-alias-addr-m = ["GWID-" / "ALIAS-"] (alias-addr / "$")
; The -m at the end indicates use in the media field
ex-vcci = "VCCI-" vcci
ex-cid = "CID-" cid
ex-bcg = "BCG-" bcg
ex-portid = "PORT-" portid
ex-vpi = "VPI-" vpi
ex-vci = "VCI-" vci
ex-vpci = "VPCI-" vpci
vcci = generic-U16
cid = generic-U8
bcg = generic-U8
portid = 1*32 (HEXDIG)
vpi = generic-U12
vci = generic-U16
vpci = generic-U16
transport-fmts = generic-transport-fmts / known-transport-fmts / "- -"
Rajesh Kumar, Mohamed Mostafa. 61
generic-transport-fmts = generic-transport 1*(space fmt)
generic-transport = 1*(alpha-numeric / "/")
fmt = 1*(alpha-numeric)
known-transport-fmts = aal1-transport space aal1-fmt-list /
aal2-transport space aal2-fmt-list
*(space aal2-transport space aal2-fmt-list) /
aal5-transport space aal5-fmt-list /
rtp-transport space rtp-fmt-list /
tn-proto space tn-fmt-list /
h323c-proto "-"
h323c-proto = "H323c"
; h323c-proto used for RTCP control ports in H.323 annex C applications
; tn-proto and tn-fmt-list per rfc2848
aal1-transport = "AAL1" "/" aal1-transport-list
aal1-transport-list = "ATMF" / "ITU" / "custom" / "IEEE:" 6(HEXDIG) /
corporate-name
corporate-name = 1*(safe)
aal2-transport = "AAL2" "/" aal2-transport-list
aal2-transport-list = aal1-transport-list
aal5-transport = "AAL5" "/" aal5-transport-list
aal5-transport-list = aal1-transport-list
rtp-transport = "RTP" "/" rtp-transport-list
rtp-transport-list = "AVP"
aal1-fmt-list = (payload-type *(space payload-type)) / "-"
payload-type = decimal-uchar
aal5-fmt-list = aal1-fmt-list
rtp-fmt-list = aal1-fmt-list
aal2-fmt-list = (profile *(space profile)) / "-"
profile = decimal-uchar
attribute-fields = *("a=" attribute EOL)
attribute = known-attribute / (generic-att-field ":" att-value) /
generic-att-field
generic-att-field = 1*(alpha-numeric)
att-value = byte-string
known-attribute = atm-attribute / PIMT-attribute / rfc2327-attribute
; PINT-attribute as defined in rfc2848
; rfc2327 attribute as defined in that rfc
atm-attribute =
"atmmap" ":" payload-type space encoding-name /
"eecid" ":" eecid /
"aalType" ":" aal-type /
"silenceSupp" ":" silenceSuppEnable space silenceTimer space suppPref
space sidUse space fxnslevel /
"ecanf" ":" ecanEnable space ecanType /
"ecanb" ":" ecanEnable space ecanType /
"gcf" ":" gcEnable space gcLvl /
"gcb" ":" gcEnable space gcLvl /
"profileDesc" ":" aal2-transport space profile space
1*(profile-row) /
"vsel" ":" 1*(encoding-name space packet-length space
packet-time space) /
"dsel" ":" fxIncl space
Rajesh Kumar, Mohamed Mostafa. 62
1*(encoding-name space packet-length space
packet-time space) /
"fsel" ":" 1*(encoding-name space packet-length space
packet-time space) /
"capability" ":" (asc / atc / 1*(alpha-numeric)) space capab-subtype /
"qosclass" ":" qosclass /
"bcob" ":" bcob /
"stc" ":" stc /
"upcc" ":" upcc /
"atmQOSfparms" ":" cdvType space acdv space ccdv space actd space cctd
space aclr /
"atmQOSbparms" ":" cdvType space acdv space ccdv space actd space cctd
space aclr /
"aal2QOSfparms" ":" byte-string /
"aal2QOSbparms" ":" byte-string /
"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 /
"aal2FtrfcDesc" ":" byte-string /
"aal2BtrfcDesc" ":" byte-string /
"abrFparms" ":" nrm space trm space cdf space adtf /
"abrBparms" ":" nrm space trm space cdf space adtf /
"clkrec" ":" clkrec /
"fec" ":" fecEnable /
"prtfl" ":" partialFill /
"bearertype" ":" bearerType space localInitiation /
"structure" ":" structureEnable space blksz /
"sbc" ":" sbc /
"fcpsSDUsize" ":" cpcs /
"bcpsSDUsize" ":" cpcs /
"aal2CPS" ":" cidCount space timerCU /
"aal2sscs3661" ":" adt space ted space fsssar space bsssar /
"aal2sscs3662" ":" sap space circuitMode space frameMode space faxDemod
space cas space dtmf space mfall space mfr1
space mfr2 space PCMencoding space fmaxFrame space bmaxFrame /
"aalApp" ":" aalApp /
"lij" ":" sci space lsn /
"anycast" ":" atmGroupAddress space cdStd space
conScpTyp space conScpSel /
"cache" ":" cacheEnable space cacheTimer
"chain" ":" chainPointer
eec-id = hex-U32
aalType = "AAL1" / "AAL2" / "AAL3/4" / "AAL5" / "USER_DEFINED_AAL"
silenceSuppEnable = on-off-or-null
silenceTimer = generic-U16-or-null
suppPref = "standard" / "custom" / "-"
sidUse = "No SID" / "Fixed Noise" / "Sampled Noise" / "-"
fxnslevel = generic-U8-or-null
ecanEnable = on-off-or-null
ecanType = "G165" / "G168" / "-"
gcEnable = on-off-or-null
gcLvl = generic-U16-or-null
profile-row = uuiCodeRange space encoding-name space packet-length
space packet-time space
uuiCodeRange = decimal-uchar "-" decimal-uchar / "-"
encoding-name = "-" /
"PCMG" / "SIDG" / "SID729" /
Rajesh Kumar, Mohamed Mostafa. 63
"PCMU" / "G726-32" / "G723" / "PCMA" / "G722" / "G728" /
"G729" / "X-G729a" / "X-G729b" / "X-G729ab" / "X-G726-16" /
"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-G727-32" /
"X-CCD" / "X-CCD-CAS" / "GSM" / "X-GSM-HR" / "X-GSM-EFR" /
"X-GSM-EHR" / "X-FXDMOD-3" / "1016" / "DVI4" / "L16" / "LPC" /
"MPA" / "QCELP" / "H263" / "H263-1998" /
"JPEG" / "H261" / "MPV" / "MP2T" / "nv" / "RED" / "X-RED" /
"CelB" / "L8" / "VDVI" / "MP1S" / "MP2P"
packet-length = decimal-U8-or-null
packet-time = decimal-U8-or-null
fxIncl = on-off-or-null
asc = "CBR" / "nrt-VBR" / "rt-VBR" / "UBR" / "ABR" / "GFR"
atc = "DBR" / "SBR" / "ABT/IT" / "ABT/DT" / "ABR"
capab-subtype = decimal-U8-or-null
qosclass = decimal-U8-or-null
bcob = generic-U8
stc = decimal-uchar
upcc = decimal-uchar
cdvType = "PP" / "2P" / "-"
acdv = decimal-U32-or-null
ccdv = decimal-U32-or-null
actd = decimal-U16-or-null
cctd = decimal-U16-or-null
aclr = decimal-U8-or-null
clpLvl = "0" / "0+1" / "-"
pcr = decimal-U32-or-null
scr = decimal-U32-or-null
mbs = decimal-U16-or-null
cdvt = decimal-U32-or-null
mcr = decimal-U32-or-null
mfs = decimal-U16-or-null
fd = on-off-or-null
te = on-off-or-null
nrm = generic-U8-or-null
trm = generic-U8-or-null
cdf = generic-U8-or-null
adtf = generic-U16-or-null
clkrec = "NULL" / "SRTS" / "ADAPTIVE"
fecEnable = "NULL" / "LOSS_SENSITIVE" / "DELAY_SENSITIVE"
partialFill = generic-U8
bearerType = "PVC" / "SVC" / "CID"
localInitiation = on-off-or-null
structureEnable = on-off-or-null
blksz = generic-U16-or-null
sbc = generic-U8
cpcs = generic-U16
cidCount = generic-U8-or-null
timerCU = decimal-U32-or-null
adt = on-off-or-null
ted = on-off-or-null
fsssar = generic-U16-or-null
bsssar = generic-U16-or-null
sap = "AUDIO" / "MULTIRATE" / "-"
circuitMode = on-off-or-null
frameMode = on-off-or-null
faxDemod = on-off-or-null
cas = on-off-or-null
dtmf = on-off-or-null
mfall = on-off-or-null
Rajesh Kumar, Mohamed Mostafa. 64
mfr1 = on-off-or-null
mfr2 = on-off-or-null
PCMencoding = "PCMA" / "PCMU" / "-"
fmaxframe = generic-U16-or-null
bmaxframe = generic-U16-or-null
aalApp =
AAL5app = "-" /
"itu_h323c" / "af83" / "assuredSSCOP" / "nonassuredSSCOP" /
"itu_i3661"/ "itu_i3662"/ "itu_i3651" /
"itu_i3652" / "itu_i3653" / "FRF11" / "FRF5" / "FRF8" / "itu_h2221"
sci = generic-U8-or-null
lsn = generic-U32-or-null
atmGroupAddress = atm-type-addr
cdStd = generic-U8-or-null
conScpTyp = generic-U8-or-null
conScpSel = generic-U8-or-null
cacheEnable = on-off-or-null
cacheTimer = generic-U32-or-null
chainPointer = "NEXT" / "PREVIOUS" / "NULL"
References References
[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.
[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
Rajesh Kumar, Mohamed Mostafa. 59
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,
by the RFC that evolves out of draft-ietf-avt-profile-new-09.txt. by the RFC that evolves out of draft-ietf-avt-profile-new-09.txt.
[4] ATMF UNI 3.1 Specification, af-uni-0010.002. Of special [4] ATMF UNI 3.1 Specification, af-uni-0010.002. Of special
interest for this document is Section 5.4.5.5, ATM Adaptation interest for this document is Section 5.4.5.5, ATM Adaptation
Layer Parameters. Layer Parameters.
[5] ATMF UNI 4.0 Signaling Specification, af-sig-0061.000. [5] ATMF UNI 4.0 Signaling Specification, af-sig-0061.000.
skipping to change at line 3596 skipping to change at line 3968
Specification, version 2.0, af-vtoa-0078.000, Jan. 97. Specification, version 2.0, af-vtoa-0078.000, Jan. 97.
[8] ATMF Voice and Telephony over ATM - ATM Trunking using AAL1 for [8] ATMF Voice and Telephony over ATM - ATM Trunking using AAL1 for
Narrowband Services, version 1.0, af-vtoa-0089.000, July 1997. Narrowband Services, version 1.0, af-vtoa-0089.000, July 1997.
[9] ATMF Specifications of (DBCES) Dynamic Bandwidth Utilization - [9] ATMF Specifications of (DBCES) Dynamic Bandwidth Utilization -
in 64kbps Timeslot Trunking over ATM - using CES, af-vtoa- in 64kbps Timeslot Trunking over ATM - using CES, af-vtoa-
0085.000, July 1997. 0085.000, July 1997.
[10] ITU-T I.363.1, B-ISDN ATM Adaptation Layer Specification: Type [10] ITU-T I.363.1, B-ISDN ATM Adaptation Layer Specification: Type
Rajesh Kumar, Mohamed Mostafa. 65
1 AAL, August 1996. 1 AAL, August 1996.
[11] ITU-T I.363.2, B-ISDN ATM Adaptation Layer Specification: Type [11] ITU-T I.363.2, B-ISDN ATM Adaptation Layer Specification: Type
2 AAL, Sept. 1997. 2 AAL, Sept. 1997.
[12] ITU-T I.366.1, Segmentation and Reassembly Service Specific [12] ITU-T I.366.1, Segmentation and Reassembly Service Specific
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.
skipping to change at line 3632 skipping to change at line 4006
[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.
[20] rfc2474, Definition of the Differentiated Services Field (DS [20] rfc2474, Definition of the Differentiated Services Field (DS
Field) in the IPv4 and IPv6 Headers. K. Nichols, S. Blake, F. Field) in the IPv4 and IPv6 Headers. K. Nichols, S. Blake, F.
Baker, D. Black. December 1998. Baker, D. Black. December 1998.
[21] ITU-T I.363.5, B-ISDN ATM Adaptation Layer Specification: Type [21] ITU-T I.363.5, B-ISDN ATM Adaptation Layer Specification: Type
5 AAL, Aug. 1996. 5 AAL, Aug. 1996.
Rajesh Kumar, Mohamed Mostafa. 60
[22] ATMF PNNI 1.0, af-pnni-0055.000, March 1996. [22] ATMF PNNI 1.0, af-pnni-0055.000, March 1996.
[23] ietf-avt-rtp-new-05.txt, Oct. 21, 1999, RTP: A Transport [23] ietf-avt-rtp-new-05.txt, Oct. 21, 1999, RTP: A Transport
Protocol for Real-Time Applications. Protocol for Real-Time Applications.
[24] ietf-avt-profile-new-07.txt, Oct. 21, 1999, RTP Profile for [24] ietf-avt-profile-new-07.txt, Oct. 21, 1999, RTP Profile for
Audio and Video Conferences with Minimal Control. Audio and Video Conferences with Minimal Control.
[25] Media Gateway Control Protocol (MGCP), Mauricio Arango, Isaac [25] Media Gateway Control Protocol (MGCP), Mauricio Arango, Isaac
Elliott, Christian Huitema, Scott Pickett, Version 1.0, Elliott, Christian Huitema, Scott Pickett, Version 1.0,
skipping to change at line 3659 skipping to change at line 4031
[27] IP Authentication Header, R. Atkinson, August 1995, RFC1826. [27] IP Authentication Header, R. Atkinson, August 1995, RFC1826.
[28] ITU I.371, Traffic Control and Congestion Control in the BISDN. [28] ITU I.371, Traffic Control and Congestion Control in the BISDN.
[29] ITU E.191, BISDN Numbering and Addressing. [29] ITU E.191, BISDN Numbering and Addressing.
[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
Rajesh Kumar, Mohamed Mostafa. 66
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)
- 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.
skipping to change at line 3695 skipping to change at line 4069
oriented network service. oriented network service.
[41] I.365.3, B-ISDN ATM adaptation layer sublayers: service [41] I.365.3, B-ISDN ATM adaptation layer sublayers: service
specific coordination function to provide the specific coordination function to provide the
connection-oriented transport service. connection-oriented transport service.
[42] I.365.4, B-ISDN ATM adaptation layer sublayers: Service specific [42] I.365.4, B-ISDN ATM adaptation layer sublayers: Service specific
convergence sublayer for HDLC applications. convergence sublayer for HDLC applications.
[43] Q.2110, B-ISDN ATM adaptation layer - service specific connection [43] Q.2110, B-ISDN ATM adaptation layer - service specific connection
Rajesh Kumar, Mohamed Mostafa. 61
oriented protocol (SSCOP). oriented protocol (SSCOP).
[44] af-vtoa-0113.000, ATM trunking using AAL2 for narrowband services. [44] af-vtoa-0113.000, ATM trunking using AAL2 for narrowband services.
[45] H.323-2, Packet-based multimedia communications systems. [45] H.323-2, Packet-based multimedia communications systems.
[46] af-vtoa-0083.000, Voice and Telephony Over ATM to the Desktop. [46] af-vtoa-0083.000, Voice and Telephony Over ATM to the Desktop.
[47] I.356, BISDN ATM layer cell transfer performance. [47] I.356, BISDN ATM layer cell transfer performance.
skipping to change at line 3721 skipping to change at line 4093
[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
using AAL2. using AAL2.
Rajesh Kumar, Mohamed Mostafa. 67
[53] FRF.5, Frame Relay/ATM PVC Network Interworking Implementation Agreement. [53] FRF.5, Frame Relay/ATM PVC Network Interworking Implementation Agreement.
[54] FRF.8, Frame Relay/ATM PVC Service Interworking Implementation Agreement. [54] FRF.8, Frame Relay/ATM PVC Service Interworking 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
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,
David Auerbach, Robert Biskner, Bruce Buffam, Steve Casner, Alex Clemm, David Auerbach, Robert Biskner, Bruce Buffam, Steve Casner, Alex Clemm,
Bill Foster, Snehal Karia, Raghu Thirumalai Rajan, Joe Stone, Bruce Bill Foster, Snehal Karia, Raghu Thirumalai Rajan, Joe Stone, Bruce
Thompson, Dan Wing and Ken Young of Cisco, Michael Brown, Rade Thompson, Dan Wing and Ken Young of Cisco, Michael Brown, Rade
Gvozdanovic, Graeme Gibbs, Tom-PT Taylor, Mark Watson 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 and Groves of Ericsson, Charles Eckel of Vovida Networks, Tom Jepsen and
Chris Gallon of Fujitsu, Mahamood Hussain of Hughes Software Systems, Chris Gallon of Fujitsu, Mahamood Hussain of Hughes Software Systems,
Sean Sheedy of nCUBE Corporation and Narendra Tulpule of Trillium Digital Sean Sheedy of nCUBE Corporation and Narendra Tulpule of Intel. The authors
systems. The authors also wish to thank the ISC device control group, and also wish to thank the ISC device control group, and
the MMUSIC and MEGACO subgroups of the IETF, especially Bill Foster, Jeorg the MMUSIC and MEGACO subgroups of the IETF, especially Bill Foster, Jeorg
Ott, Sean Sheedy and Brian Rosen for their help in the preparation of this Ott, Sean Sheedy and Brian Rosen for their help in the preparation of this
document. document. Finally, thanks are due to Naren Tulpule of Intel whose ABNF
grammar was adapted for this document.
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
Email: rkumar@cisco.com Email: rkumar@cisco.com
Mohamed Mostafa Mohamed Mostafa
Rajesh Kumar, Mohamed Mostafa. 62
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
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
skipping to change at line 3781 skipping to change at line 4156
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
are included on all such copies and derivative works. However, this are included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of Internet organizations, except as needed for the purpose of
Rajesh Kumar, Mohamed Mostafa. 68
developing Internet standards in which case the procedures for developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than followed, or as required to translate it into languages other than
English. English.
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. 63 Rajesh Kumar, Mohamed Mostafa. 69
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