draft-ietf-sigtran-m2ua-03.txt   draft-ietf-sigtran-m2ua-04.txt 
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Greg Sidebottom Greg Sidebottom
Nortel Networks Nortel Networks
Ram Dantu Ram Dantu
IPMobile IPMobile
Tom George Tom George
Alcatel Alcatel
Expires in six months March 2000 Expires in six months March 2000
SS7 MTP2-User Adaptation Layer SS7 MTP2-User Adaptation Layer
<draft-ietf-sigtran-m2ua-03.txt> <draft-ietf-sigtran-m2ua-04.txt>
Status of This Memo Status of This Memo
This document is an Internet-Draft and is in full conformance with all This document is an Internet-Draft and is in full conformance with all
provisions of Section 10 of RFC 2026. Internet-Drafts are working provisions of Section 10 of RFC 2026. Internet-Drafts are working
documents of the Internet Engineering Task Force (IETF), its areas, documents of the Internet Engineering Task Force (IETF), its areas,
and its working groups. Note that other groups may also distribute and its working groups. Note that other groups may also distribute
working documents as Internet-Drafts. working documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
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TABLE OF CONTENTS TABLE OF CONTENTS
1. Introduction..............................................2 1. Introduction..............................................2
1.1 Scope..................................................2 1.1 Scope..................................................2
1.2 Terminology............................................3 1.2 Terminology............................................3
1.3 Signaling Transport Architecture.......................3 1.3 Signaling Transport Architecture.......................3
1.4 Services Provide by the M2UA Adaptation Layer..........6 1.4 Services Provide by the M2UA Adaptation Layer..........6
1.5 Function Provided by the M2UA Layer....................8 1.5 Function Provided by the M2UA Layer....................8
1.6 Definition of the M2UA Boundaries......................9 1.6 Definition of the M2UA Boundaries......................9
2. Protocol Elements.........................................9 2. Conventions...............................................9
2.1 Common Message Header.................................10 3. Protocol Elements.........................................9
2.2 M2UA Message Header...................................11 3.1 Common Message Header.................................10
2.3 M2UA Messages.........................................11 3.2 M2UA Message Header...................................11
3. Procedures...............................................20 3.3 M2UA Messages.........................................11
3.1 Procedures to Support Service in Section 1.4.1........20 4. Procedures...............................................20
3.2 Procedures to Support Service in Section 1.4.2........21 4.1 Procedures to Support Service in Section 1.4.1........20
3.3 Procedures to Support Service in Section 1.4.3........21 4.2 Procedures to Support Service in Section 1.4.2........21
4. Examples of MTP2 User Adaptation (M2UA) Procedures.......26 4.3 Procedures to Support Service in Section 1.4.3........21
4.1 Establishment of associations between SG and MGC......26 5. Examples of MTP2 User Adaptation (M2UA) Procedures.......26
5.1 Establishment of associations between SG and MGC......26
examples examples
4.2 MTP Level 2 / MTP Level 3 Boundary Examples...........28 5.2 MTP Level 2 / MTP Level 3 Boundary Examples...........28
4.3 Layer Management Communication Examples...............29 5.3 Layer Management Communication Examples...............29
5. Security.................................................30 6. Security.................................................30
6. IANA Considerations......................................31 7. IANA Considerations......................................31
7. Acknowledgements.........................................31 8. Acknowledgements.........................................31
8. References...............................................32 9. References...............................................32
9. Author's Addresses.......................................33 10. Author's Addresses.......................................33
1. Introduction 1. Introduction
1.1 Scope 1.1 Scope
There is a need for SCN signaling protocol delivery from an Signaling There is a need for SCN signaling protocol delivery from an Signaling
Gateway (SG) to a Media Gateway Controller (MGC) or IP Signaling Point Gateway (SG) to a Media Gateway Controller (MGC) or IP Signaling Point
(IPSP). The delivery mechanism should meet the following criteria: (IPSP). The delivery mechanism should meet the following criteria:
* Support for MTP Level 2 / MTP Level 3 interface boundary * Support for MTP Level 2 / MTP Level 3 interface boundary
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In the process of fail-over or fail-back, it is recommended that in the In the process of fail-over or fail-back, it is recommended that in the
case of ASPs supporting call processing, stable calls do not fail. It case of ASPs supporting call processing, stable calls do not fail. It
is possible that calls in ˘transition÷ may fail, although measures of is possible that calls in ˘transition÷ may fail, although measures of
communication between the ASPs involved can be used to mitigate this. communication between the ASPs involved can be used to mitigate this.
For example, the two ASPs may share call state via shared memory, or may For example, the two ASPs may share call state via shared memory, or may
use an ASP to ASP protocol to pass call state information. use an ASP to ASP protocol to pass call state information.
1.3.5 Client/Server Model 1.3.5 Client/Server Model
The SG takes on the role of server while the ASP is the client. ASPs It is recommended that the SG take on the role of server while the
must initiate the SCTP association to the SG. ASP is the client. ASPs should initiate the SCTP association to the
SG.
The SCTP (and UDP/TCP) Registered User Port Number Assignment for M2UA The SCTP (and UDP/TCP) Registered User Port Number Assignment for M2UA
is 2904. is 2904.
1.4 Services Provided by the M2UA Adaptation Layer 1.4 Services Provided by the M2UA Adaptation Layer
The SS7 MTP3/MTP2(MTP2-User) interface is retained at the termination The SS7 MTP3/MTP2(MTP2-User) interface is retained at the termination
point in the IP network, so that the M2UA protocol layer is required to point in the IP network, so that the M2UA protocol layer is required to
provide the equivalent set of services to its users as provided by the provide the equivalent set of services to its users as provided by the
MTP Level 2 to MTP Level 3. MTP Level 2 to MTP Level 3.
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avoiding head of line blocking. For that reason, a stream should be used avoiding head of line blocking. For that reason, a stream should be used
per SS7 signaling link terminated by the Signaling Gateway. The SS7 per SS7 signaling link terminated by the Signaling Gateway. The SS7
signaling link can be identified by the optional Interface Identifier signaling link can be identified by the optional Interface Identifier
in the M2UA specific message header (refer to Section 2.2). in the M2UA specific message header (refer to Section 2.2).
1.5.4 Seamless SS7 Network Management Interworking 1.5.4 Seamless SS7 Network Management Interworking
If the SG loses the SCTP association to the MGC, it should follow If the SG loses the SCTP association to the MGC, it should follow
MTP 2 processor outage procedures [2]. MTP 2 processor outage procedures [2].
1.5.5 Management Inhibit/Uninhibit 1.5.5 Active Association Control
Local Management at an ASP or SG may wish to stop traffic across an
SCTP association in order to temporarily remove the association from
service or to perform testing and maintenance activity. The function
could optionally be used to control the start of traffic on to a newly-
available SCTP association.
1.5.6 Active Association Control
At an SG, an Application Server list may contain active and inactive At an SG, an Application Server list may contain active and inactive
ASPs to support ASP loads-haring and fail-over procedures. When, for ASPs to support ASP loads-haring and fail-over procedures. When, for
example, both a primary and a back-up ASP are available, M2UA peer example, both a primary and a back-up ASP are available, M2UA peer
protocol is required to control which ASP is currently active. The protocol is required to control which ASP is currently active. The
ordered list of ASPs within a logical Application Server is kept ordered list of ASPs within a logical Application Server is kept
updated in the SG to reflect the active Application Server Process(es). updated in the SG to reflect the active Application Server Process(es).
1.6 Definition of the M2UA Boundaries 1.6 Definition of the M2UA Boundaries
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The upper layer and layer management primitives provided by SCTP are The upper layer and layer management primitives provided by SCTP are
provided in Reference [6] Section 9. provided in Reference [6] Section 9.
1.6.4 Definition of Layer Management / M2UA Boundary 1.6.4 Definition of Layer Management / M2UA Boundary
M-ERROR M-ERROR
M-SCTP ESTABLISH M-SCTP ESTABLISH
M-SCTP STATUS M-SCTP STATUS
M-ASP STATUS M-ASP STATUS
2.0 Protocol Elements 2.0 Conventions
The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD, SHOULD
NOT, RECOMMENDED, NOT RECOMMENDED, MAY, and OPTIONAL, when they appear
in this document, are to be interpreted as described in [RFC2119].
3.0 Protocol Elements
This section describes the format of various messages used in this This section describes the format of various messages used in this
protocol. protocol.
2.1 Common Message Header 3.1 Common Message Header
The protocol messages for MTP2-User Adaptation require a message The protocol messages for MTP2-User Adaptation require a message
structure which contains a version, message type, message length, and structure which contains a version, message type, message length, and
message contents. This message header is common among all signaling message contents. This message header is common among all signaling
protocol adaptation layers: protocol adaptation layers:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Version | Spare | Message Type | | Version | Spare | Message Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Message Length | | Message Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 3 Common Message Header Figure 3 Common Message Header
All fields in an M2UA message MUST be transmitted in the network byte All fields in an M2UA message MUST be transmitted in the network byte
order, unless otherwise stated. order, unless otherwise stated.
2.1.1 Version 3.1.1 Version
The version field (vers) contains the version of the M2UA adapation The version field (vers) contains the version of the M2UA adapation
layer. The supported versions are: layer. The supported versions are:
0000 0001 Release 1.0 protocol Release 1.0 0x1
2.1.2 Message Type 3.1.2 Message Type
The valid message types are defined in Section 2.2.2 and the message The valid message types are defined in Section 3.2.2 and the message
contents are described in Section 2.3. Each message can contain contents are described in Section 3.3. Each message can contain
parameters. parameters.
The following list contains the message types for the defined messages. The following list contains the message types for the defined messages.
MTP2 User Adaptatation (MAUP) Messages MTP2 User Adaptatation (MAUP) Messages
Data 0601 Data 0x0601
Establish Request 0602 Establish Request 0x0602
Establish Confirm 0603 Establish Confirm 0x0603
Release Request 0604 Release Request 0x0604
Release Confirm 0605 Release Confirm 0x0605
Release Indication 0606 Release Indication 0x0606
State Request 0607 State Request 0x0607
State Confirm 0608 State Confirm 0x0608
State Indication 0609 State Indication 0x0609
Data Retrieval Request 060a Data Retrieval Request 0x060a
Data Retrieval Confirm 060b Data Retrieval Confirm 0x060b
Data Retrieval Indication 060c Data Retrieval Indication 0x060c
Data Retrieval Complete Indication 060d Data Retrieval Complete Indication 0x060d
Application Server Process Maintenance (ASPM) Messages Application Server Process Maintenance (ASPM) Messages
ASP Up (ASPUP) 0301 ASP Up 0x0301
ASP Down (ASPDN) 0302 ASP Down 0x0302
ASP Active (ASPAC) 0401 Heartbeat 0x0303
ASP Inactive (ASPIA) 0402 ASP Up Ack 0x0304
ASP Down Ack 0x0305
ASP Active 0x0401
ASP Inactive 0x0402
ASP Active 0x0403
ASP Inactive 0x0404
Management (MGMT) Messages Management (MGMT) Messages
Error 0000 Error 0x0000
Notify 0x0001
2.1.3 Message Length 3.1.3 Message Length
The Message length defines the length of the message in octets, not The Message length defines the length of the message in octets, not
including the header. including the header.
2.2 M2UA Message Header 3.1.4 Variable-Length Parameter Format
IUA messages consist of a Common Header followed by zero or more
variable-length parameters, as defined by the message type. The
variable-length parameters contained in a message are defined in a
Tag-Length-Value format as shown below.
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Parameter Tag | Parameter Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
\ \
/ Parameter Value /
\ \
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Parameter Tag: 16 bits (unsigned integer)
The Type field is a 16 bit identifier of the type of parameter. It takes
a value of 0 to 65534.
The value of 65535 is reserved for IETF-defined extensions. Values
other than those defined in specific parameter description are reserved
for use by the IETF.
Parameter Length: 16 bits (unsigned integer)
The Parameter Length field contains the size of the parameter in bytes,
including the Parameter Tag, Parameter Length, and Parameter Value
fields. Thus, a parameter with a zero-length Parameter Value field
would have a Length field of 4. The Parameter Length does not include
any padding bytes.
Parameter Value: variable-length.
The Parameter Value field contains the actual information to be
transferred in the parameter.
The total length of a parameter (including Tag, Parameter Length and Value
fields) MUST be a multiple of 4 bytes. If the length of the parameter is
not a multiple of 4 bytes, the sender pads the Parameter at the end (i.e.,
after the Parameter Value field) with all zero bytes. The length of the
padding is NOT included in the parameter length field. A sender should
NEVER pad with more than 3 bytes. The receiver MUST ignore the padding
bytes.
3.2 M2UA Message Header
In addition to the common message header, there will be a M2UA specific In addition to the common message header, there will be a M2UA specific
message header. The M2UA specific message header will immediately message header. The M2UA specific message header will immediately
follow the common message header, but will only be used with MAUP and follow the common message header, but will only be used with MAUP
MGMT messages. messages.
This message header will contain the Interface Identifier. The This message header will contain the Interface Identifier. The
Interface Identifier identifies the physical interface at the SG for Interface Identifier identifies the physical interface at the SG for
which the signaling messages are sent/received. The format of the which the signaling messages are sent/received. The format of the
Interface Identifier parameter is an integer, the values of which are Interface Identifier parameter is an integer, the values of which are
assigned according to network operator policy. The values used are of assigned according to network operator policy. The values used are of
local significance only, coordinated between the SG and ASP. local significance only, coordinated between the SG and ASP.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x1) | Length=4 | | Tag (0x1) | Length=4 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface Identifier | | Interface Identifier |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4 M2UA Message Header Figure 4 M2UA Message Header
The Tag value for Interface Identifier is 0x1. The length is always The Tag value for Interface Identifier is 0x1. The length is always
set to a value of 4. set to a value of 8.
2.3 M2UA Messages 3.3 M2UA Messages
The following section defines the messages and parameter contents. The The following section defines the messages and parameter contents. The
M2UA messages will use the common message header (Figure 3) and the M2UA messages will use the common message header (Figure 3) and the
M2UA message header (Figure 4). M2UA message header (Figure 4).
2.3.1 MTP2 User Adaptation Messages 3.3.1 MTP2 User Adaptation Messages
2.3.1.1 Data 3.3.1.1 Data
The Data message contains an SS7 MTP2-User Protocol Data Unit (PDU). The The Data message contains an SS7 MTP2-User Protocol Data Unit (PDU). The
Data message contains the protocol data. Data message contains the protocol data.
The format for the Data Message parameters is as follows: The format for the Data Message parameters is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Protocol Data | | Protocol Data |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Protocol Data field contains the MTP2-User application message in The Protocol Data field contains the MTP2-User application message in
network byte order. network byte order.
2.3.1.2 Establish (Request, Confirmation) 3.3.1.2 Establish (Request, Confirmation)
The Establish Request message is used to establish the link or to The Establish Request message is used to establish the link or to
indicate that the channel has been established. Note that the gateway indicate that the channel has been established. Note that the gateway
may already have the SS7 link established at its layer. If so, upon may already have the SS7 link established at its layer. If so, upon
receipt of an Establish Request, the gateway takes no action except to receipt of an Establish Request, the gateway takes no action except to
send an Establish Confirm. send an Establish Confirm.
The mode (Normal of Emergency) for bringing the link in service is The mode (Normal of Emergency) for bringing the link in service is
defaulted to Normal. The State Request (described in Section 2.3.1.4 defaulted to Normal. The State Request (described in Section 3.3.1.4
below) can be used to change the mode to Emergency. below) can be used to change the mode to Emergency.
2.3.1.3 Release (Request, Indication, Confirmation) 3.3.1.3 Release (Request, Indication, Confirmation)
This Release Request message is used to release the channel. The This Release Request message is used to release the channel. The
Release Confirm and Indication messages are used to indicate that the Release Confirm and Indication messages are used to indicate that the
channel has been released. channel has been released.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reason | | Reason |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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RELEASE_PHYS 0x1 Physical layer alarm generated release RELEASE_PHYS 0x1 Physical layer alarm generated release
RELEASE_SIOS 0x2 Receipt of SIOS RELEASE_SIOS 0x2 Receipt of SIOS
RELEASE_T6 0x3 Release due to expiration of Timer T6 RELEASE_T6 0x3 Release due to expiration of Timer T6
RELEASE_T7 0x4 Release due to expiration of Timer T7 RELEASE_T7 0x4 Release due to expiration of Timer T7
RELEASE_BSN 0x5 Release due to invalid BSN (2 of 3) RELEASE_BSN 0x5 Release due to invalid BSN (2 of 3)
RELEASE_FIB 0x6 Release due to invalid FIB (2 of 3) RELEASE_FIB 0x6 Release due to invalid FIB (2 of 3)
RELEASE_SUERM 0x7 Release due to failure reported by SUERM RELEASE_SUERM 0x7 Release due to failure reported by SUERM
RELEASE_IAC 0x8 Release due to initial alignment failed RELEASE_IAC 0x8 Release due to initial alignment failed
RELEASE_OTHER 0x9 Other reason SS7 link out-of-service RELEASE_OTHER 0x9 Other reason SS7 link out-of-service
2.3.1.4 State (Request, Confirm) 3.3.1.4 State (Request, Confirm)
The State Request message can be sent from a MGC to cause an action The State Request message can be sent from a MGC to cause an action
on a particular SS7 link supported by the Signaling Gateway. The on a particular SS7 link supported by the Signaling Gateway. The
gateway sends a State Confirm to the MGC if the action has been success- gateway sends a State Confirm to the MGC if the action has been success-
fully completed. The State Confirm reflects that state value received fully completed. The State Confirm reflects that state value received
in the State Request message. in the State Request message.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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STATUS_LPO_CLEAR 0x1 Request local processor outage STATUS_LPO_CLEAR 0x1 Request local processor outage
recovered recovered
STATUS_EMER_SET 0x2 Request emergency alignment STATUS_EMER_SET 0x2 Request emergency alignment
procedure procedure
STATUS_EMER_CLEAR 0x3 Request normal alignment (cancel STATUS_EMER_CLEAR 0x3 Request normal alignment (cancel
emergency) procedure emergency) procedure
STATUS_FLUSH_BUFFERS 0x4 Flush transmit and retransmit STATUS_FLUSH_BUFFERS 0x4 Flush transmit and retransmit
buffers buffers
STATUS_CONTINUE 0x5 Continue STATUS_CONTINUE 0x5 Continue
2.3.1.5 State Indication 3.3.1.5 State Indication
The MTP2 State Indication message can be sent from a gateway to an The MTP2 State Indication message can be sent from a gateway to an
ASP to indicate a condition on a link. ASP to indicate a condition on a link.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| State | | State |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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EVENT_ENTER_CONG 0x2 Entered a congested state EVENT_ENTER_CONG 0x2 Entered a congested state
EVENT_EXIT_CONG 0x3 Exited a congested state EVENT_EXIT_CONG 0x3 Exited a congested state
EVENT_PHYS_UP 0x4 Physical interface up EVENT_PHYS_UP 0x4 Physical interface up
EVENT_PHYS_DOWN 0x5 Physical interface down EVENT_PHYS_DOWN 0x5 Physical interface down
EVENT_PROTOCOL_ERR 0x6 Protocol error occurred EVENT_PROTOCOL_ERR 0x6 Protocol error occurred
EVENT_REM_ENTER_CONG 0xc Remote entered congestion EVENT_REM_ENTER_CONG 0xc Remote entered congestion
EVENT_REM_EXIT_CONG 0xd Remote exited congestion EVENT_REM_EXIT_CONG 0xd Remote exited congestion
EVENT_REM_ENTER_PO 0xe Remote entered processor outage EVENT_REM_ENTER_PO 0xe Remote entered processor outage
EVENT_REM_EXIT_PO 0xf Remote exited processor outage EVENT_REM_EXIT_PO 0xf Remote exited processor outage
2.3.1.6 Retrieval (Request, Confirm) 3.3.1.6 Retrieval (Request, Confirm)
The MTP2 Retrieval Request message is used during the MTP Level 3 The MTP2 Retrieval Request message is used during the MTP Level 3
changeover procedure to request the BSN, to retrieve PDUs from the changeover procedure to request the BSN, to retrieve PDUs from the
retransmit queue or to flush PDUs from the retransmit queue. retransmit queue or to flush PDUs from the retransmit queue.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Action | | Action |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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ACTION_DROP_MSGS 0x3 Drop the PDUs in the retransmit queue ACTION_DROP_MSGS 0x3 Drop the PDUs in the retransmit queue
In the Retrieval Request message, the fsn_bsn field contains the FSN of In the Retrieval Request message, the fsn_bsn field contains the FSN of
the far end if the action is ACTION_RTRV_MSGS. the far end if the action is ACTION_RTRV_MSGS.
When the Signaling Gateway sends a Retrieval Confirm to this request, When the Signaling Gateway sends a Retrieval Confirm to this request,
it echos the action and puts the BSN in the fsn_bsn field if the action it echos the action and puts the BSN in the fsn_bsn field if the action
was ACTION_RTRV_BSN. If there is a failure in retrieving the BSN, the was ACTION_RTRV_BSN. If there is a failure in retrieving the BSN, the
fsn_bsn should contain a -1 (0xffffffff). fsn_bsn should contain a -1 (0xffffffff).
2.3.1.7 Retrieval Indication 3.3.1.7 Retrieval Indication
The Retrieval Indication message is sent by the Signaling Gateway The Retrieval Indication message is sent by the Signaling Gateway
with a PDU from the retransmit queue. The Retrieval Indication with a PDU from the retransmit queue. The Retrieval Indication
message does not contain the Action or fsn_bsn fields, just a PDU from message does not contain the Action or fsn_bsn fields, just a PDU from
the retransmit queue. the retransmit queue.
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| PDU from retransmit queue | | PDU from retransmit queue |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
2.3.1.8 Retrieval Complete Indication 3.3.1.8 Retrieval Complete Indication
The MTP2 Retrieval Complete Indication message is exactly the same as The MTP2 Retrieval Complete Indication message is exactly the same as
the MTP2 Retrieval Indication message except that it also indicates that the MTP2 Retrieval Indication message except that it also indicates that
it contains the last PDU from the retransmit queue. it contains the last PDU from the retransmit queue.
2.3.2 Application Server Process Maintenance (ASPM) Messages 3.3.2 Application Server Process Maintenance (ASPM) Messages
The ASPM messages will only use the common message header. The ASPM messages will only use the common message header.
2.3.2.1 ASP UP (ASPUP) 3.3.2.1 ASP UP (ASPUP)
The ASP UP (ASPUP) message is used to indicate to a remote M2UA peer The ASP UP (ASPUP) message is used to indicate to a remote M2UA peer
that the Adaptation layer is ready to receive traffic or maintenance that the Adaptation layer is ready to receive traffic or maintenance
messages. messages.
The ASPUP message contains the following parameters: The ASPUP message contains the following parameters:
Adaptation Layer Identifer (optional) Adaptation Layer Identifer (optional)
Protocol Identifier (optional) Protocol Identifier (optional)
INFO String (optional) INFO String (optional)
skipping to change at page 16, line 29 skipping to change at page 16, line 29
| Adaptation Layer Identifier* | | Adaptation Layer Identifier* |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x4) | Length | | Tag (0x4) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| INFO String* | | INFO String* |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The optional INFO String parameter can carry any meaningful 8-BIT ASCII The optional INFO String parameter can carry any meaningful 8-bit ASCII
character string along with the message. Length of the INFO String character string along with the message. Length of the INFO String
parameter is from 0 to 255 characters. No procedures are presently parameter is from 0 to 255 characters. No procedures are presently
identified for its use but the INFO String may be used for debugging identified for its use but the INFO String may be used for debugging
purposes. purposes.
The optional Adaptation Layer Identifier (ALI) is a string that The optional Adaptation Layer Identifier (ALI) is a string that
identifies the adaptation layer. This string must be set to "M2UA" identifies the adaptation layer. This string must be set to "M2UA"
which results in a length of 4. The ALI would normally only be used in which results in a length of 8. The ALI would normally only be used in
the initial ASP Up message across a new SCTP association to ensure both the initial ASP Up message across a new SCTP association to ensure both
peers are assuming the same adaptation layer protocol. peers are assuming the same adaptation layer protocol.
Note: Strings are padded to 32-bit boundaries. The length field 3.3.3.2 ASP Up Ack
indicates the end of the string.
2.3.2.2 ASP Down (ASPDN) The ASP UP Ack message is used to acknowledge an ASP-Up message received
from a remote IUA peer.
The ASP Down (ASPDN) message is used to indicate to a remote M2UA peer The ASPUP Ack message contains the following parameters:
that the adaptation layer is not ready to receive traffic or maintenance
messages.
The ASPDN message contains the following parameters: Adaptation Layer Identifer (optional)
INFO String (optional)
The format for ASPUP Ack Message parameters is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x2) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Adaptation Layer Identifier* |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x4) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| INFO String* |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The format and description of the optional Info String parameter is the
same as for the ASP UP message (See Section 3.3.3.1.)
The format and description of the optional Adaptation Layer Identifier (ALI)
parameter is the same as for the ASP UP message (See Section 3.3.3.1).
3.3.3.3 ASP Down (ASPDN)
The ASP Down (ASPDN) message is used to indicate to a remote IUA peer
that the adaptation layer is not ready to receive traffic or
maintenance messages.
The ASPDN message contains the following parameters
Reason Reason
INFO String (Optional) INFO String (Optional)
The format for the ASPDN message parameters is as follows: The format for the ASPDN message parameters is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reason | | Reason |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x4) | Length | | Tag (0x4) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| INFO String* | | INFO String* |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The format and description of the optional Info String parameter is the The format and description of the optional Info String parameter is the
same as for the ASP Up message (See Section 2.3.2.1.) same as for the ASP Up message (See Section 3.3.2.1.)
The Reason parameter indicates the reason that the remote M2UA The Reason parameter indicates the reason that the remote M2UA
adaptation layer is unavailable. The valid values for Reason are shown adaptation layer is unavailable. The valid values for Reason are shown
in the following table. in the following table.
Value Description Value Description
0x1 Management Inhibit 0x1 Management Inhibit
2.3.2.3 ASP Active (ASPAC) 3.4.4 ASP Down Ack
The ASP Down Ack message is used to acknowledge an ASP-Down message
received from a remote IUA peer.
The ASP Down Ack message contains the following parameters:
Reason
INFO String (Optional)
The format for the ASPDN Ack message parameters is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reason |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x4) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| INFO String* |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The format and description of the optional Info String parameter is the
same as for the ASP UP message (See Section 3.3.3.1.)
The format of the Reason parameter is the same as for the ASP-Down message
(See Section 3.3.3.3).
3.3.3.5 ASP Active (ASPAC)
The ASPAC message is sent by an ASP to indicate to an SG that it is The ASPAC message is sent by an ASP to indicate to an SG that it is
Active and ready to be used. Active and ready to be used.
The ASPAC message contains the following parameters: The ASPAC message contains the following parameters
Type Type
Interface Identifier (Optional) Interface Identifier (Optional)
INFO String (Optional) INFO String (Optional)
The format for the ASPAC message is as follows: The format for the ASPAC message is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x4) | Length | | Tag (0x4) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| INFO String* | | INFO String* |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Type parameter identifies the traffic mode of operation of the ASP The Type parameter identifies the traffic mode of operation of the ASP
within an AS. The valid values for Type are shown in the following table. within an AS. The valid values for Type are shown in the following
table.
Value Description Value Description
0x1 Over-ride 0x1 Over-ride
0x2 Load-share 0x2 Load-share
0x3 New traffic
Within a particular Routing Context, only one Type can be used. The Within a particular Interface Identifier, only one Type can be used.
Over-ride value indicates that the ASP is operating in Over-ride mode, The Over-ride value indicates that the ASP is operating in Over-ride
where the ASP takes over all traffic in an Application Server (i.e., mode, where the ASP takes over all traffic in an Application Server
primary/back-up operation), over-riding any currently active ASPs in (i.e., primary/back-up operation), over-riding any currently active
the AS. In loadshare mode, the ASP will share in the traffic distribution ASPs in the AS. In Load-share mode, the ASP will share in the
with any other currently active ASPs. In New Traffic mode the ASP wishes traffic distribution with any other currently active ASPs.
to take on traffic in the AS but does not expect to receive messages
related to calls/transactions that are pending completion in another ASP.
An SG that receives an ASPAC with an incorrect type for a particular
Interface Identifier will respond with an Error Message.
The optional Interface Identifiers parameter contains a list of The optional Interface Identifiers parameter contains a list of
Interface Identifier integers indexing the Application Server traffic Interface Identifier integers indexing the Application Server traffic
that the sending ASP is configured/registered to receive. There is that the sending ASP is configured/registered to receive. There is
one-to-one relationship between an Interface Identifier and an AS Name. one-to-one relationship between an Interface Identifier and an AS
If no Interface Identifiers are present, then the message is intended Name.
for all Interface Identifiers supported by the SG.
An SG that receives an ASPAC with an incorrect type for a particular
Interface Identifier will respond with an Error Message.
The format and description of the optional Info String parameter is the The format and description of the optional Info String parameter is the
same as for the ASP Up message (See Section 2.3.2.1.) same as for the ASP UP message (See Section 3.3.3.1.)
2.3.2.4 ASP Inactive (ASPIA) A node that receives an ASPAC with an incorrect Type for a particular
Interface Identifier will respond with an Error Message (Cause: Invalid
Traffic Handling Mode).
3.3.3.6 ASP Active Ack
The ASPAC Ack message is used to acknowledge an ASP-Active message
received from a remote IUA peer.
The ASPAC Ack message contains the following parameters:
Type
Interface Identifier (Optional)
INFO String (Optional)
The format for the ASPAC Ack message is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface Identifiers* |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x4) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| INFO String* |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The format and description of the optional Info String parameter is the
same as for the ASP UP message (See Section 3.3.3.1.)
The format of the Type and Interface Identifier parameters is the same
as for the ASP Active message (See Section 3.3.3.5).
3.3.3.7 ASP Inactive (ASPIA)
The ASPIA message is sent by an ASP to indicate to an SG that it is no The ASPIA message is sent by an ASP to indicate to an SG that it is no
longer an active ASP to be used from within a list of ASPs. The SG will longer an active ASP to be used from within a list of ASPs. The SG will
respond with an ASPIA message and either discard incoming messages or respond with an ASPIA message and either discard incoming messages or
buffer for a timed period and then discard. buffer for a timed period and then discard.
The ASPIA message contains the following parameters: The ASPIA message contains the following parameters
Type Type
Interface Identifiers (Optional) Interface Identifiers (Optional)
INFO String (Optional) INFO String (Optional)
The format for the ASPIA message parameters is as follows: The format for the ASPIA message parameters is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type | | Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0xx) | Length | | Tag (0x1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface Identifiers* | | Interface Identifiers* |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x4) | Length | | Tag (0x4) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| INFO String* | | INFO String* |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Type parameter identifies the traffic mode of operation of the ASP The Type parameter identifies the traffic mode of operation of the ASP
within an AS. The valid values for Type are shown in the following table. within an AS. The valid values for Type are shown in the following table.
Value Description Value Description
0x1 Over-ride 0x1 Over-ride
0x2 Load-share 0x2 Load-share
0x3 Graceful Withdrawal
The format and description of the optional Interface Identifiers and The format and description of the optional Interface Identifiers and
Info String parameters is the same as for the ASP Active message (See Info String parameters is the same as for the ASP Active message (See
Section 2.3.2.3.) If no Interface Identifiers are present, then the Section 3.3.3.3.)
message is intended for all Interface Identifiers supported by the SG.
2.3.3 Layer Management (MGMT) Messages The optional Interface Identifiers parameter contains a list of
Interface Identifier integers indexing the Application Server traffic
that the sending ASP is configured/registered to receive, but does not
want to receive at this time.
2.3.3.1 Error (ERR) 3.3.3.8 ASP Inactive Ack
The ERR message is sent when an invalid value is found in an incoming The ASPIA Ack message is used to acknowledge an ASP-Inactive message
message. received from a remote IUA peer.
The ASPIA Ack message contains the following parameters:
Type
Routing Context (Optional)
INFO String (Optional)
The format for the ASPIA Ack message is as follows:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x6) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Routing Context* |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x4) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| INFO String* |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The format and description of the optional Info String parameter is
the same as for the ASP UP message (See Section 3.3.3.1.)
The format of the Type and Routing Context parameters is the same as
for the ASP-Inctive message (See Section 3.3.3.7).
3.4.9 Heartbeat (BEAT)
The Heartbeat message is optionally used to ensure that the IUA peers
are still available to each other. It is recommended for use when
the IAU runs over a transport layer other than the SCTP, which has its
own heartbeat.
The BEAT message contains no parameters.
3.3.3 Layer Management (MGMT) Messages
3.3.3.1 Error (ERR)
The Error message is used to notify a peer of an error event
associated with an incoming message. For example, the message type
might be unexpected given the current state, or a parameter value might
be invalid.
The ERR message contains the following parameters: The ERR message contains the following parameters:
Error Code Error Code
Diagnostic Information (optional) Diagnostic Information (optional)
The format for the ERR message is as follows: The format for the ERR message is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
skipping to change at page 19, line 44 skipping to change at page 19, line ?
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Error Code parameter indicates the reason for the Error Message. The Error Code parameter indicates the reason for the Error Message.
The Error parameter value can be one of the following values: The Error parameter value can be one of the following values:
Invalid Version 0x1 Invalid Version 0x1
Invalid Interface Identifier 0x2 Invalid Interface Identifier 0x2
Invalid Adaptation Layer Identifier 0x3 Invalid Adaptation Layer Identifier 0x3
Invalid Message Type 0x4 Invalid Message Type 0x4
Invalid Traffic Handling Mode 0x5 Invalid Traffic Handling Mode 0x5
Invalid Stream Identifier 0x5 Unexpected Message 0x6
Protocol Error 0x7
Invalid Stream Identifier 0x8
The optional Diagnostic information can be any information germain to The optional Diagnostic information can be any information germain to
the error condition, to assist in identification of the error condition. the error condition, to assist in identification of the error condition.
In the case of an Invalid Version Error Code the Diagnostic information In the case of an Invalid Version Error Code the Diagnostic information
includes the supported Version parameter. In the other cases, the includes the supported Version parameter. In the other cases, the
Diagnostic information may be the first 40 bytes of the offending message. Diagnostic information may be the first 40 bytes of the offending message.
2.3.3.2 Notify (NTFY) 3.3.3.2 Notify (NTFY)
The Notify message used to provide autonomous notification of M2UA events. The Notify message used to provide an autonomous indication of IUA
events to an IUA peer.
The NTFY message contains the following parameters: The NTFY message contains the following parameters:
Status Type Status Type
Status Identification Status Identification
Interface Identifiers (Optional) Interface Identifiers (Optional)
INFO String (Optional) INFO String (Optional)
The format for the NTFY message is as follows: The format for the NTFY message is as follows:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Status Type | Status Identification | | Status Type | Status Identification |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0xx) | Length | | Tag (0x1) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Interface Identifiers* | | Interface Identifiers* |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Tag (0x4) | Length | | Tag (0x4) | Length |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| INFO String* | | INFO String* |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The Status Type parameter identifies the type of the Notify message. Following are the valid Status Type values: The Status Type parameter identifies the type of the Notify message.
The following are the valid Status Type values:
Value Description Value Description
0x1 Application Server state change (AS_State_Change) 0x1 Application Server state change (AS_State_Change)
0x2 Application Server Process state change (ASP_State_Change) 0x2 Other
0x3 Other
The Status Information parameter contains more detailed information for the notification, based on the value of the Status Type. If the Status Type is AS_State_Change the following Status Information values are used: The Status Information parameter contains more detailed information for
the notification, based on the value of the Status Type. If the Status
Type is AS_State_Change the following Status Information values are used:
Value Description Value Description
0x1 Application Server Down (AS_Down) 0x1 Application Server Down (AS_Down)
0x2 Application Server Up (AS_Up) 0x2 Application Server Up (AS_Up)
0x3 Application Server Active (AS_Active) 0x3 Application Server Active (AS_Active)
0x4 Application Server Pending (AS_Pending) 0x4 Application Server Pending (AS_Pending)
0x5 Alternate ASP Active
These notifications are sent from an SG to an ASP upon a change in status of a particular Application Server. The value reflects the new state of the Application Server.
If the Status type is ASP_State_Change, the Status Information values are:
Value Description
0x1 Application Server Process (ASP) Down
0x2 Application Server Process (ASP) Up
0x3 Application Server Process (ASP) Active
0x4 Application Server Process (ASP) Active_Old
0x5 Application Server Process (ASP) Active_New
These notifications are sent from an SG to an ASP upon a change in status These notifications are sent from an SG to an ASP upon a change in status
of a particular Application Server process within the ASP list of a of a particular Application Server. The value reflects the new state of
particular Application Server. The value reflects the new state of the the Application Server.
Application Server Process.
If the Status Type is Other, then the following Status Information values If the Status Type is Other, then the following Status Information values
are defined: are defined:
Value Description Value Description
0x1 Insufficient ASP resources active in AS 0x1 Insufficient ASP resources active in AS
This notification is not based on the SG reporting the state change of an This notification is not based on the SG reporting the state change of an
ASP or AS. For the value defined the SG is indicating to an ASP(s) in ASP or AS. For the value defined the SG is indicating to an ASP(s) in
the AS that another ASP is required in order to handle the load of the AS. the AS that another ASP is required in order to handle the load of the AS.
The format and description of the optional Interface Identifiers and Info The format and description of the optional Interface Identifiers and
String parameters is the same as for the ASP Active message (See Info String parameters is the same as for the ASP Active message
Section 2.3.2.3.) (See Section 3.3.3.3.)
3.0 Procedures 4.0 Procedures
The M2UA layers needs to respond to various primitives it receives from The M2UA layers needs to respond to various primitives it receives from
other layers as well as messages it receives from the peer-to-peer other layers as well as messages it receives from the peer-to-peer
messages. This section describes various procedures involved in messages. This section describes various procedures involved in
response to these events. response to these events.
3.1 Procedures to Support Service in Section 1.4.1 4.1 Procedures to Support Service in Section 1.4.1
These procedures achieve the M2UA layer's "Transport of MTP Level 2 / These procedures achieve the M2UA layer's "Transport of MTP Level 2 /
MTP Level 3 boundary" service. MTP Level 3 boundary" service.
3.1.1 MTP Level 2 / MTP Level 3 Boundary Procedures 4.1.1 MTP Level 2 / MTP Level 3 Boundary Procedures
On receiving a primitive from the local upper layer, the M2UA layer will On receiving a primitive from the local upper layer, the M2UA layer will
send the corresponding MAUP message (see Section 2) to its peer. The send the corresponding MAUP message (see Section 2) to its peer. The
M2UA layer must fill in various fields of the common and specific headers M2UA layer must fill in various fields of the common and specific headers
correctly. In addition the message needs to be sent on the SCTP stream correctly. In addition the message needs to be sent on the SCTP stream
that corresponds to the SS7 link. that corresponds to the SS7 link.
3.1.2 MAUP Message Procedures 4.1.2 MAUP Message Procedures
On receiving MAUP messages from a peer M2UA layer, the M2UA layer on an On receiving MAUP messages from a peer M2UA layer, the M2UA layer on an
SG or MGC needs to invoke the corresponding layer primitives to the SG or MGC needs to invoke the corresponding layer primitives to the
local MTP Level 2 or MTP Level 3 layer. local MTP Level 2 or MTP Level 3 layer.
3.2 Procedures to Support Service in Section 1.4.2 4.2 Procedures to Support Service in Section 1.4.2
These procedures achieve the M2UA layer's "Support for Communication These procedures achieve the M2UA layer's "Support for Communication
between Layer Managements" service. between Layer Managements" service.
3.2.1 Layer Management Primitives Procedure 4.2.1 Layer Management Primitives Procedure
On receiving these primitives from the local layer, the M2UA layer will On receiving these primitives from the local layer, the M2UA layer will
send the corresponding MGMT message (Error) to its peer. The M2UA layer send the corresponding MGMT message (Error) to its peer. The M2UA layer
must fill in the various fields of the common and specific headers must fill in the various fields of the common and specific headers
correctly. correctly.
3.2.2 MGMT message procedures 4.2.2 MGMT message procedures
Upon receipt of MGMT messages the M2UA layer must invoke the corresponding Upon receipt of MGMT messages the M2UA layer must invoke the corresponding
Layer Management primitives (M-ERROR) to the local layer management. Layer Management primitives (M-ERROR) to the local layer management.
3.3 Procedures to Support Service in Section 1.4.3 4.3 Procedures to Support Service in Section 1.4.3
These procedures achieve the M2UA layer's "Support for management of These procedures achieve the M2UA layer's "Support for management of
active associations between SG and MGC" service. active associations between SG and MGC" service.
3.3.1 State Maintenance 4.3.1 State Maintenance
The M2UA layer on the SG maintains the state of each AS, in each The M2UA layer on the SG maintains the state of each AS, in each
Appliction Server that it is configured to receive traffic. Appliction Server that it is configured to receive traffic.
3.3.1.1 ASP States 4.3.1.1 ASP States
The state of each ASP, in each AS that it is configured, is maintained The state of the each ASP, in each AS that it is configured, is
in the M2UA layer in the SG. The state of a particular ASP in a maintained in the IUA layer on the SG. The state of an ASP changes
particular AS changes due to events. The events include: due to events. The events include
* Reception of messages from the peer M2UA layer at the ASP * Reception of messages from peer IUA layer at that ASP
* Reception of some messages from the peer M2UA layer at other ASPs * Reception of some messages from the peer IUA layer at other
in the AS ASPs in the AS
* Reception of indications from the SCTP layer * Reception of indications from SCTP layer
* Switch-over Time triggers * Switch-over Time triggers
The ASP state transition diagram is shown in Figure 4. The possible The ASP state transition diagram is shown in Figure 4. The possible
states of an ASP are: states of an ASP are the following:
ASP-DOWN: The remote M2UA peer at the ASP is unavailable and/or the SCTP ASP-DOWN Application Server Process is unavailable and/or the SCTP
association is down. Initially all ASPs will be in this state. association is down. Initially all ASPs will be in this state.
ASP-UP: The remote M2UA peer at the ASP is available (and the SCTP ASP-UP The remote IUA peer at the ASP is available (and the SCTP
association is up) but application traffic is stopped. association is up) but application traffic is stopped.
ASP-ACTIVE: The remote M2UA peer at the ASP is available and application ASP-ACTIVE The remote IUA peer at the ASP is available and
traffic is active (for a particular Routing Context or set of Routing application traffic is active.
Contexts).
ASP-ACT-OLD: The remote M2UA peer at the ASP is available and application
traffic is active (for a particular Routing Context or set of Routing
Contexts), but for draining of current call/transactions only (i.e., no
new calls/transactions)
ASP-ACT-NEW: The remote M2UA peer at the ASP is available and application Figure 4 ASP State Transition Diagram
traffic is active (for a particular Routing Context or set of Routing
Contexts), but for new calls/transactions only (i.e., not for traffic
related to completing calls/transactions in another ASP).
+-------------+ +-------------+
+----------------------| | +----------------------| |
| Some other /| ASP-ACTIVE |<--------\ | Alternate +-------| ASP-ACTIVE |<------------+
| ASP / +-------------+ | | ASP | +-------------+ |
| Takeover / ^ | | Ts | Takeover | ^ | |
| / ASP | | ASP | | | ASP | | ASP |
| / Active | | Inactive | | | Active | | Inactive | ASP
| v | v | | | | v |Takeover
| +-------------+ +-------------+ +-------------+ | | +-------------+ |
| | | | | | | | | | |-------------+
| | ASP-ACT-OLD |----->| ASP-UP |------>| ASP-ACT-NEW | | +------>| ASP-UP |-------------+
| +-------------+ Ts / +-------------+ ASP +-------------+ | +-------------+ |
| | ASP Inactive ^ | Takeover | | ^ | |
|<---| | | |
| | | |
ASP Down/ | ASP | | ASP Down / | ASP ASP Down/ | ASP | | ASP Down / | ASP
SCTP CDI | Up | | SCTP CDI | Down/ SCTP CDI | Up | | SCTP CDI | Down/
| | v | SCTP | | v | SCTP
| +-------------+ | CDI | +-------------+ | CDI
| | | | | | | |
+------------------>| |<-------------+ +--------------------->| |<------------+
| ASP-DOWN | | ASP-DOWN |
+-------------+ +-------------+
SCTP CDI: The local SCTP layer's Communication Down Indication to the SCTP CDI The local SCTP layer's Communication Down Indication to the
Upper Layer Protocol (M2UA) on an SG. The local SCTP will send this Upper Layer Protocol (IUA) on an SG. The local SCTP will send this
indication when it detects the loss of connectivity to the ASP's peer indication when it detects the loss of connectivity to the ASP's peer
SCTP layer. SCTP layer.
Ts: Switch-over Time Triggers. This timer is configurable by the Ts Switch-over Time Triggers. This timer is configurable by the
Operator on a per AS basis. Operator on a per AS basis. The default value of this timer should
be three seconds.
3.3.1.2 AS States 4.3.1.2 AS States
The state of the AS is maintained in the M2UA layer on the SG. The The state of the AS is maintained in the IUA layer on the SG.
state of an AS changes due to events. These events include:
The state of an AS changes due to events. These events include the
following:
* ASP state transitions * ASP state transitions
* Recovery timer triggers * Recovery timer triggers
The possible states of an AS are: The possible states of an AS are the following:
AS-DOWN: The Application Server is unavailable. This state implies that AS-DOWN The Application Server is unavailable. This state implies
all related ASPs are in the ASP-DOWN state for this AS. Initially the that all related ASPs are in the ASP-DOWN state for this AS.
AS will be in this state. Initially the AS will be in this state.
AS-UP: The Application Server is available but no application traffic is AS-UP The Application Server is available but no application traffic
active (i.e., one or more related ASPs are in the ASP-UP state, but is active (i.e., one or more related ASPs are in the ASP-UP state,
none in the ASP-Active state). but none in the ASP-Active state).
AS-ACTIVE: The Application Server is available and application traffic AS-ACTIVE The Application Server is available and application traffic
is active. This state implies that one ASP is in the ASP-ACTIVE state. is active. This state implies that one ASP is in the ASP-ACTIVE state.
AS-PENDING: An active ASP has transitioned from active to inactive or AS-PENDING An active ASP has transitioned from active to inactive or
down and it was the last remaining active ASP in the AS. A recovery down and it was the last remaining active ASP in the AS. A recovery
timer T(r) will be started and all incoming SCN messages will be queued timer T(r) will be started and all incoming SCN messages will be
by the SG. If an ASP becomes active before T(r) expires, the AS will queued by the SG. If an ASP becomes active before T(r) expires, the
move to AS-ACTIVE state and all the queued messages will be sent to the AS will move to AS-ACTIVE state and all the queued messages will be
active ASP. sent to the active ASP.
If T(r) expires before an ASP becomes active, the SG stops queuing If T(r) expires before an ASP becomes active, the SG stops queuing
messages and discards all previously queued messages. The AS will move messages and discards all previously queued messages. The AS will move
to AS-UP if at least one ASP is in ASP-UP state, otherwise it will move to AS-UP if at least one ASP is in ASP-UP state, otherwise it will move
to AS-DOWN state. to AS-DOWN state.
Figure 5 AS State Transition Diagram
+----------+ one ASP trans ACTIVE +-------------+ +----------+ one ASP trans ACTIVE +-------------+
| |------------------------>| | | |------------------------>| |
| AS-UP | | AS-ACTIVE | | AS-UP | | AS-ACTIVE |
| | | | | | | |
| |< -| | | |< -| |
+----------+ \ / +-------------+ +----------+ \ / +-------------+
^ | \ Tr Trigger / ^ | ^ | \ Tr Trigger / ^ |
| | \ at least one / | | | | \ at least one / | |
| | \ ASP in UP / | | | | \ ASP in UP / | |
| | \ / | | | | \ / | |
| | \ / | | | | \ / | |
| | \ /---/ | | | | \ /---/ | |
one ASP | | \ / one ASP | | ACTIVE ASP one ASP | | \ / one ASP | | Last ACTIVE ASP
trans | | all ASP \-/----\ trans | | trans to UP or trans | | all ASP \-/----\ trans to | | trans to UP or
to UP | | trans to / \ ACTIVE | | ACTIVE ASP to UP | | trans to / \ ACTIVE | | DOWN
| | DOWN / \ | | SCTP CLN | | DOWN / \ | |
| | / \ | | | | / \ | |
| | / \ | | | | / \ | |
| | /all ASP \ | | | | /all ASP \ | |
| v / trans to \ | v | v / trans to \ | v
+----------+ / DOWN \ +-------------+ +----------+ / DOWN \ +-------------+
| |<--/ -| | | |<--/ -| |
| AS-DOWN | | AS-PENDING | | AS-DOWN | | AS-PENDING |
| | | (queueing) | | | | (queueing) |
| |<------------------------| | | |<------------------------| |
+----------+ Tr Trigger no ASP +-------------+ +----------+ Tr Trigger no ASP +-------------+
in UP state in UP state
Tr = Recovery Timer Tr = Recovery Timer
Figure 5: AS State Transition Diagram 4.3.2 ASPM procedures for primitives
3.3.2 ASPM procedures for primitives
Before the establishment of an SCTP association the ASP state at both Before the establishment of an SCTP association the ASP state at both
the SG and ASP is assumed to be "Down". the SG and ASP is assumed to be "Down".
As the ASP is responsible for initiating the setup of an SCTP As the ASP is responsible for initiating the setup of an SCTP
association to an SG, the M2UA layer at an ASP receives an M-SCTP association to an SG, the IUA layer at an ASP receives an M-SCTP
ESTABLISH request primitive from the Layer Management, the M2UA layer ESTABLISH request primitive from the Layer Management, the IUA layer
will try to establish an SCTP association with the remote M2UA peer at will try to establish an SCTP association with the remote IUA peer at
an SG. Upon reception of an eventual SCTP-Communication Up confirm an SG. Upon reception of an eventual SCTP-Communication Up confirm
primitive from the SCTP, the M2UA layer will invoke the primitive M-SCTP primitive from the SCTP, the IUA layer will invoke the primitive
ESTABLISH confirm to the Layer Management. M-SCTP ESTABLISH confirm to the Layer Management.
At the SG, the M2UA layer will receive an SCTP Communication Up At the SG, the IUA layer will receive an SCTP Communication Up
indication primitive from the SCTP. The M2UA layer will then invoke the indication primitive from the SCTP. The IUA layer will then invoke
primitive M-SCTP ESTABLISH indication to the Layer Management. the primitive M-SCTP ESTABLISH indication to the Layer Management.
Once the SCTP association is established, The M2UA layer at an ASP will Once the SCTP association is establishedand assuming that the local
then find out the state of its local M2UA-user from the Layer Management IUA-User is ready, the local ASP IUA Application Server Process
using the primitive M-ASP STATUS. Based on the status of the local Maintenance (ASPM) function will initiate the ASPM procedures, using
M2UA-User, the local ASP M2UA Application Server Process Maintenance the ASP-Up/-Down/-Active/-Inactive messages to convey the ASP-state to
(ASPM) function will initiate the ASPM procedures, using the ASP-Up/- the SG - see Section 4.3.3.
Down/-Active/-Inactive messages to convey the ASP-state to the SG - see
Section 3.3.3.
If the M2UA layer subsequently receives an SCTP-Communication Down The Layer Management and the IUA layer on SG can communicate the
indication from the underlying SCTP layer, it will inform the Layer status of the application server using the M-AS STATUS primitives.
Management by invoking the M-SCTP STATUS indication primitive. The The Layer Managements and the IUA layers on both the SG and ASP
can communicate the status of an SCTP association using the
M-SCTP STATUS primitives.
If the Layer Management on SG or ASP wants to bring down an SCTP
association for management reasons, they would send M-SCTP RELEASE
request primitive to the local IUA layer. The IUA layer would release
the SCTP association and upon receiving the SCTP Communication Down
indication from the underlying SCTP layer, it would inform the local
Layer Management using M-SCTP RELEASE confirm primitive.
If the IUA layer receives an SCTP-Communication Down indication
from the underlying SCTP layer, it will inform the Layer
Management by invoking the M-SCTP RELEASE indication primitive. The
state of the ASP will be moved to "Down" at both the SG and ASP. state of the ASP will be moved to "Down" at both the SG and ASP.
At an ASP, the Layer Management may try to reestablish the SCTP At an ASP, the Layer Management may try to reestablish the SCTP
association using M-SCTP ESTABLISH request primitive. association using M-SCTP ESTABLISH request primitive.
3.3.3 ASPM procedures for peer-to-peer messages 4.3.3 ASPM procedures for peer-to-peer messages
All ASPM messages are sent on a sequenced stream to ensure ordering. All ASPM messages are sent on a sequenced stream to ensure ordering.
SCTP stream Š0Ă is used. SCTP stream Š0Ă is used.
3.3.3.2 ASP-Up 4.3.3.2 ASP-Up
After an ASP has successfully established an SCTP association to an SG, After an ASP has successfully established an SCTP association to an SG,
the SG waits for the ASP to send an ASP-Up message, indicating that the the SG waits for the ASP to send an ASP-Up message, indicating that the
ASP M2UA peer is available. The ASP is always the initiator of the ASP IUA peer is available. The ASP is always the initiator of the
ASP-Up exchange. ASP-Up exchange.
When an ASP-Up message is received at an SG and internally the ASP is not When an ASP-Up message is received at an SG and internally the ASP is
locked-out for local management reasons, the SG marks the remote ASP as not considered locked-out for local management reasons, the SG marks
ŠUpĂ. The SG responds with an Notify (ASP-Up) message to the ASP in the remote ASP as Up. The SG responds with an ASP-Up Ack message in
acknowledgement. The SG sends a Notify (ASP-Up) message in response to acknowledgement. The SG sends an-Up Ack message in response to a
a received ASP-Up message from the ASP even if the ASP is already marked received ASP-Up message even if the ASP is already marked as "Up"
as ˘Up÷ at the SG. at the SG.
If for any local reason the SG cannot respond with an ASP-Up, the SG If for any local reason the SG cannot respond with an ASP-Up, the SG
responds to a ASP-Up with a ASP-Down message. responds to a ASP-Up with a Notify (ASP-Down) message.
At the ASP, the Notify (ASP-Up) message received from the SG is not At the ASP, the ASP-Up Ack message received from the SG is not
acknowledged by the ASP. If the ASP does not receive a response from acknowledged by the ASP. If the ASP does not receive a response from
the SG, or an ASP-Down is received, the ASP may resend ASP-Up messages the SG, or an ASP-Down is received, the ASP may resend ASP-Up messages
every 2 seconds until it receives a Notify (ASP-Up) message from the SG. every 2 seconds until it receives a Notify (ASP-Up) message from the
The ASP may decide to reduce the frequency (say to every 5 seconds) if a SG. The ASP may decide to reduce the frequency (say to every 5
Notify (ASP-Up) is not received after a few tries. seconds) if an ASP-Up Ack is not received after a few tries.
The ASP must wait for the Notify (ASP-Up) message from the SG before The ASP must wait for the ASP-Up Ack message from the SG before
sending any ASP traffic control messages (ASPAC or ASPIA) or Data sending any ASP traffic control messages (ASPAC or ASPIA) or Data
messages or it will risk message loss. If the SG receives Data messages messages or it will risk message loss. If the SG receives Data
before an ASP Up is received, the SG should discard. messages before an ASP Up is received, the SG should discard.
3.3.3.2 ASP-Down 4.3.3.2 ASP-Down
The ASP will send an ASP-Down to an SG when the ASP is to be removed from The ASP will send an ASP-Down to an SG when the ASP is to be removed
the list of ASPs in all Application Servers that it is a member. from the list of ASPs in all Application Servers that it is a member.
The SG marks the ASP as ˘Down÷ and returns an Notify (ASP-Down) message The SG marks the ASP as "Down" and returns an ASP-Down Ack message to
to the ASP if one of the following events occur: the ASP if one of the following events occur:
- an ASP-Down message is received from the ASP, - an ASP-Down message is received from the ASP,
- another ASPM message is received from the ASP and the SG has - another ASPM message is received from the ASP and the SG has
locked out the ASP for management reasons. locked out the ASP for management reasons.
The SG sends a Notify (ASP-Down) message in response to a received ASP- The SG sends anASP-Down Ack message in response to a received ASP-Down
Down message from the ASP even if the ASP is already marked as ˘Down÷ at message from the ASP even if the ASP is already marked as "Down" at
the SG. the SG.
If the ASP does not receive a response from the SG, the ASP may send ASP- If the ASP does not receive a response from the SG, the ASP may send
Down messages every 2 seconds until it receives a ASP-Down message from ASP-Down messages every 2 seconds until it receives an ASP-Down Ack
the SG or the SCTP association goes down. The ASP may decide to reduce message from the SG or the SCTP association goes down. The ASP may
the frequency (say to every 5 seconds) if an ASP-Down is not received decide to reduce the frequency (say to every 5 seconds) if an ASP-Down
after a few tries. Ack is not received after a few tries.
3.3.3.3 M2UA Version Control 4.3.3.3 M2UA Version Control
If a ASP-Up message with an unsupported version is received, the If a ASP-Up message with an unsupported version is received, the
receiving end responds with an Error message, indicating the version the receiving end responds with an Error message, indicating the version the
receiving node supports. receiving node supports.
This is useful when protocol version upgrades are being performed in a This is useful when protocol version upgrades are being performed in a
network. A node upgraded to a newer version should support the older network. A node upgraded to a newer version should support the older
versions used on other nodes it is communicating with. Because ASPs versions used on other nodes it is communicating with. Because ASPs
initiate the ASP-Up procedure it is assumed that the Error message would initiate the ASP-Up procedure it is assumed that the Error message would
normally come from the SG. normally come from the SG.
3.3.3.4 ASP-Active 4.3.3.4 ASP-Active
Anytime after the ASP has received a Notify (ASP-Up) acknowledgement from Any time after the ASP has received a ASP-Up Ack from the SG, the ASP
the SG, the ASP sends an ASP-Active (ASPAC) to the SG indicating that the sends an ASP-Active (ASPAC) to the SG indicating that the ASP is ready
ASP is ready to start processing traffic. In the case where an ASP is to start processing traffic. In the case where an ASP is configured/-
configured/registered to process the traffic for more than one Application registered to process the traffic for more than one Application Server
Server across an SCTP association, the ASPAC contains one or more across an SCTP association, the ASPAC contains one or more Interface
Interface Identifiers to indicate for which Application Servers the Identifiers to indicate for which Application Servers the ASPAC applies.
ASPAC applies.
When an ASP Active (ASPAC) message is received, the SG responds to the When an ASP Active (ASPAC) message is received, the SG responds to the
ASP with a Notify message acknowledging that the ASPAC was received and ASP with a ASPAC Ack message acknowledging that the ASPAC was received
starts sending traffic for the associated Application Server(s) to that and starts sending traffic for the associated Application Server(s)
ASP. to that ASP.
There are two modes of Application Server traffic handling in the SG There are two modes of Application Server traffic handling in the SG
M2UA - Over-ride, Load-balancing and New Traffic. The Type parameter in IUA - Over-ride and Load-balancing. The Type parameter in the ASPAC
the ASPAC messge indicates the mode used in a particular Application messge indicates the mode used in a particular Application Server. If
Server. If the SG determines that the mode indicates in an ASPAC is the SG determines that the mode indicates in an ASPAC is incompatible
incompatible with the traffic handling mode currently used in the AS, with the traffic handling mode currently used in the AS, the SG responds
the SG responds with an Error message indicating ˘Invalid Traffic with an Error message indicating Invalid Traffic Handling Mode.
Handling Mode÷.
In the case of an Over-ride mode AS, reception of an ASPAC message at an
SG causes the redirection of all traffic for the AS to the ASP which sent
the ASPAC. Any previously active ASP in the AS is now considered Inactive
and will no longer receive traffic within the AS. The SG responds to the
ASPAC with a Notify (ASP-Active) message to the ASP. The SG sends a
Notify (ASP-Inactive) to any previously active ASP in the AS.
In the case of a Loadshare mode AS, reception of an ASPAC message at an In the case of an Over-ride mode AS, reception of an ASPAC message at
SG causes the direction of traffic to the ASP sending the ASPAC, in an SG causes the redirection of all traffic for the AS to the ASP that
addition to all the other ASPs that are currently active in the AS. sent the ASPAC. The SG responds to the ASPAC with an ASP-Active Ack
The algorithm at the SG for loadsharing traffic within an AS to all the message to the ASP. Any previously active ASP in the AS is now
active ASPs is application and network dependent. The SG responds to considered Inactive and will no longer receive traffic from the SG
the ASPAC with a Notify (ASP-Active) message to the ASP. within the AS. The SG sends a Notify (Alternate ASP-Active) to the
previously active ASP in the AS, after stopping all traffic to that
ASP.
In the case of a New Traffic mode AS, reception of an ASPAC message at In the case of a load-share mode AS, reception of an ASPAC message at
an SG causes the direction of traffic to the ASP sending the ASPAC. an SG causes the direction of traffic to the ASP sending the ASPAC,
However, traffic related to completing calls/transactions in another ASP in addition to all the other ASPs that are currently active in the AS.
is not sent to the new ASP (i.e., new calls/transactions only). How an The algorithm at the SG for loadsharing traffic within an AS to all
SG accomplishes the differentiation of old and new transactions and any the active ASPs is application and network dependent. The algorithm
loadsharing of traffic is application and implementation dependent. The could, for example be round-robin or based on information in the Data
SG responds to the ASPAC with a Notify (ASP-Active_New) message to the ASP. message, such as Interface ID, depending on the requirements of the
After a configurable time Ts, the ASP is moved to the ASP-Active state and application and the call state handling assumptions of the collection
a Notify (ASP-Active) is sent to the ASP. Most likely, the New Traffic of ASPs in the AS. The SG responds to the ASPAC with a ASP-Active Ack
mode would not be used in M2UA. message to the ASP.
3.3.3.5 ASP Inactive 4.3.3.5 ASP Inactive
When an ASP wishes to withdraw from receiving traffic the ASP sends an When an ASP wishes to withdraw from receiving traffic within an AS,
ASP Inactive (ASPIA) to the SG. In the case where an ASP is configured/- the ASP sends an ASP Inactive (ASPIA) to the SG. In the case where
registered to process the traffic for more than one Application Server an ASP is configured/registered to process the traffic for more than
across an SCTP association, the ASPIA contains one or more Routing one Application Server across an SCTP association, the ASPIA contains
Contexts to indicate for which Application Servers the ASPIA applies. one or more Interface Ids to indicate for which Application Servers
the ASPIA applies.
There are two modes of Application Server traffic handling in the SG There are two modes of Application Server traffic handling in the SG
M2UA when withdrawing an ASP from service - Over-ride, Load-balancing IUA when withdrawing an ASP from service - Over-ride and Load-balancing.
and Graceful Withdrawal. The Type parameter in the ASPIA messge The Type parameter in the ASPIA messge indicates the mode used in a
indicates the mode used in a particular Application Server. If the SG particular Application Server. If the SG determines that the mode
determines that the mode indicates in an ASPAC is incompatible with indicates in an ASPAC is incompatible with the traffic handling mode
the traffic handling mode currently used in the AS, the SG responds currently used in the AS, the SG responds with an Error message
with an Error message indicating ˘Invalid Traffic Handling Mode÷. indicating Invalid Traffic Handling Mode.
In the case of an Over-ride mode AS, where normally another ASP has In the case of an Over-ride mode AS, where normally another ASP has
already taken over the traffic within the AS with an Over-ride ASPAC, already taken over the traffic within the AS with an Over-ride ASPAC,
the ASP which sent the ASPIA is already considered by the SG to be the ASP which sends the ASPIA is already considered by the SG to be
˘Inactive÷. A Notify (ASP_Up) message is resent to the ASP. "Inactive" (i.e., in the "Up" state). An ASPIA Ack message is sent
to the ASP, after ensuring that all traffic is stopped to the ASP.
In the case of a Loadshare mode AS, the SG moves the ASP to the In the case of a Loadshare mode AS, the SG moves the ASP to the "Up"
˘Inactive÷ state and the AS traffic is re-allocated across the remaining state and the AS traffic is re-allocated across the remaining
˘active÷ ASPs per the laoadsharing algorithm currently used within the "active" ASPs per the load-sharing algorithm currently used within
AS. A Notify (ASP-Up) message is sent to the ASP after the traffic is the AS. AnASPIA Ack message is sent to the ASP after all traffic
halted to the ASP. is halted to the ASP.
In the case of Graceful Withdrawal, the SG diverts all traffic related If no other ASPs are Active in the Application Server, the SG either
to new calls/transactions to other "active" ASPs and therafter sends only discards all incoming messages for the AS or starts buffering the
traffic related to incomplete transactons to the ASP. A Notify (ASP- incoming messages for T(r)seconds, after which messages will be
Act_Old) is sent to the ASP and the ASP is moved to the "Active_Old" state. discarded. T(r) is configurable by the network operator. If the SG
When the outstanding calls/transactions are drained, or after a receives an ASPAC from an ASP in the AS before expiry of T(r), the
configurable time Ts, the SG moves the ASP to the "Up" state and sends buffered traffic is directed to the ASP and the timer is cancelled.
a Notify (ASP-Up) message to the ASP. Most likely, Graceful Withdrawal
will not be used with M2UA.
If no other ASPs are ˘Active÷ in the Application Server, the SG either 4.3.3.5 Notify
discards all incoming messages (except messages related to an ˘Active_Old÷
ASP) for the AS or starts buffering the incoming messages for T(r)seconds
after which messages will be discarded. T(r) is configurable by the
network operator. If the SG receives an ASPAC from an ASP in the AS
before expiry of T(r), the buffered traffic is directed to the ASP and
the timer is cancelled.
4.0 Examples of MTP2 User Adaptation (M2UA) Procedures In the case where a Notify (AS-Up) message is sent by an SG that now
has no ASPs active to service the traffic, the Notify does not force
the ASP(s) receiving the message to become active. The ASPs remain in
control of what (and when) action is taken.
4.1 Establishment of associations between SG and MGC examples 4.3.3.6 Heartbeat
4.1.1 Single ASP in an Application Server (˘1+0÷ sparing) The optional Heartbeat procedures may be used when operating over
transport layers that do not have their own heartbeat mechanism for
detecting loss of the transport association (i.e., other than the
SCTP).
Once the ASP sends an ASP-Up message to the SG, the ASP sends Beat
messages periodically, subject to a provisionable timer T(beat).
The SG M3UA, upon receiving a BEAT message from the ASP, responds
with a BEAT message. If no BEAT message (or any other M3UA message),
is received from the ASP within the timer 2*T(beat), the ASP will
consider the remote M3UA as 'Down".
At the ASP, if no BEAT message (or any other M3UA message) is
received from the SG within 2*T(beat), the SG is considered
unavailable. Transmission of BEAT messages is stopped and ASP-Up
procedures are used to re-establish communication with the SG M3UA
peer.
Note: Heartbeat related events are not shown in Figure 4 "ASP state
transition diagram".
5.0 Examples of MTP2 User Adaptation (M2UA) Procedures
5.1 Establishment of associations between SG and MGC examples
5.1.1 Single ASP in an Application Server (˘1+0÷ sparing)
This scenario shows the example M2UA message flows for the establishment This scenario shows the example M2UA message flows for the establishment
of traffic between an SG and an ASP, where only one ASP is configured of traffic between an SG and an ASP, where only one ASP is configured
within an AS (no backup). It is assumed that the SCTP association is within an AS (no backup). It is assumed that the SCTP association is
already set-up. already set-up.
SG ASP1 SG ASP1
| |
|<---------ASP Up----------| |<---------ASP Up----------|
|------NTFY (ASP-Up)------>| |--------ASP-Up Ack------->|
| | | |
|<-------ASP Active--------| |<-------ASP Active--------|
|----NTFY (ASP_Active)---->| |------ASP_Active Ack----->|
| | | |
4.1.2 Two ASPs in Application Server (˘1+1÷ sparing) 5.1.2 Two ASPs in Application Server (˘1+1÷ sparing)
This scenario shows the example M2UA message flows for the establishment This scenario shows the example M2UA message flows for the establishment
of traffic between an SG and two ASPs in the same Application Server, of traffic between an SG and two ASPs in the same Application Server,
where ASP1 is configured to be ˘active÷ and ASP2 a ˘standby÷ in the event where ASP1 is configured to be ˘active÷ and ASP2 a ˘standby÷ in the event
of communication failure or the withdrawal from service of ASP1. ASP2 may of communication failure or the withdrawal from service of ASP1. ASP2 may
act as a hot, warm, or cold standby depending on the extent to which ASP1 act as a hot, warm, or cold standby depending on the extent to which ASP1
and ASP2 share call/transaction state or can communicate call state under and ASP2 share call/transaction state or can communicate call state under
failure/withdrawal events. The example message flow is the same whether failure/withdrawal events. The example message flow is the same whether
the ASP-Active messages are Over-ride or Load-share mode although typically the ASP-Active messages are Over-ride or Load-share mode although typically
this example would use an Over-ride mode. this example would use an Over-ride mode.
SG ASP1 ASP2 SG ASP1 ASP2
| | | | | |
|<--------ASP Up----------| | |<--------ASP Up----------| |
|-------TFY (ASP-Up)----->| | |-------ASP-Up Ack------->| |
| | | | | |
|<-----------------------------ASP Up----------------| |<-----------------------------ASP Up----------------|
|----------------------------NTFY (ASP-Up)---------->| |----------------------------ASP-Up Ack------------->|
| | | | | |
| | | | | |
|<-------ASP Active-------| | |<-------ASP Active-------| |
|----NTFY(ASP-Active)---->| | |-----ASP-Active Ack----->| |
| | | | | |
4.1.3 Two ASPs in an Application Server (˘1+1÷ sparing, load-sharing case) 5.1.3 Two ASPs in an Application Server (˘1+1÷ sparing, load-sharing case)
This scenario shows a similar case to Section 4.1.2 but where the two This scenario shows a similar case to Section 5.1.2 but where the two
ASPs are brought to ˘active÷ and loadshare the traffic load. In this ASPs are brought to ˘active÷ and loadshare the traffic load. In this
case, one ASP is sufficient to handle the total traffic load. case, one ASP is sufficient to handle the total traffic load.
SG ASP1 ASP2 SG ASP1 ASP2
| | | | | |
|<---------ASP Up---------| | |<---------ASP Up---------| |
|-------NTFY(ASP-Up)----->| | |---------ASP-UpAck------>| |
| | | | | |
|<------------------------------ASP Up---------------| |<------------------------------ASP Up---------------|
|-----------------------------NTFY(ASP Up)---------->| |-----------------------------ASP Up Ack------------>|
| | | | | |
| | | | | |
|<--ASP Active (Ldshr)----| | |<--ASP Active (Ldshr)----| |
|----NTFY(ASP-Active)---->| | |----ASP-Active Ack------>| |
| | | | | |
|<----------------------------ASP Active (Ldshr)-----| |<----------------------------ASP Active (Ldshr)-----|
|-----------------------------NTFY(ASP-Active)------>| |-----------------------------ASP-Active Ack-------->|
| | | | | |
4.1.4 Three ASPs in an Application Server (˘n+k÷ sparing, load-sharing case) 5.1.4 Three ASPs in an Application Server (˘n+k÷ sparing, load-sharing case)
This scenario shows the example M2UA message flows for the establishment This scenario shows the example M2UA message flows for the establishment
of traffic between an SG and three ASPs in the same Application Server, of traffic between an SG and three ASPs in the same Application Server,
where two of the ASPs are brought to ˘active÷ and share the load. In where two of the ASPs are brought to ˘active÷ and share the load. In
this case, a minimum of two ASPs are required to handle the total traffic this case, a minimum of two ASPs are required to handle the total traffic
load (2+1 sparing). load (2+1 sparing).
SG ASP1 ASP2 ASP3 SG ASP1 ASP2 ASP3
| | | | | | | |
|<------ASP Up-------| | | |<------ASP Up-------| | |
|----NTFY(ASP-Up)--->| | | |-----ASP-Up Ack---->| | |
| | | | | | | |
|<--------------------------ASP Up-------| | |<--------------------------ASP Up-------| |
|------------------------NTFY(ASP-Up)--->| | |------------------------ASP-U Ack)----->| |
| | | | | | | |
|<---------------------------------------------ASP Up--------| |<---------------------------------------------ASP Up--------|
|--------------------------------------------NTFY(ASP-Up)--->| |-------------------------------------------ASPASP-Up Ack--->|
| | | | | | | |
| | | | | | | |
|<-ASP Act. (Ldshr)--| | | |<-ASP Act (Ldshr)---| | |
|---NTFY(ASP-Act.)-->| | | |----ASP-Act Ack---->| | |
| | | | | | | |
|<--------------------ASP Act. (Ldshr)---| | |<--------------------ASP Act. (Ldshr)---| |
|----------------------NTFY(ASP-Act.)--->| | |----------------------ASP-Act Ack------>| |
| | | | | | | |
4.2 ASP Traffic Fail-over Examples 5.2 ASP Traffic Fail-over Examples
4.2.1 (1+1 Sparing, withdrawal of ASP, Back-up Over-ride) 5.2.1 (1+1 Sparing, withdrawal of ASP, Back-up Over-ride)
Following on from the example in Section 4.1.2, and ASP withdraws from Following on from the example in Section 5.1.2, and ASP withdraws from
service: service:
SG ASP1 ASP2 SG ASP1 ASP2
| | | | | |
|<-----ASP Inactive-------| | |<-----ASP Inactive-------| |
|---NTFY(ASP Inactive)--->| | |----ASP Inactive Ack---->| |
|--------------------NTFY(ASP-Inactive) (Optional)-->| |--------------------NTFY(AS-Down) (Optional)------->|
| | | | | |
|<------------------------------ ASP Active----------| |<------------------------------ ASP Active----------|
|-----------------------------NTFY(ASP-Active)------>| |-----------------------------ASP-Active Ack)------->|
| | | |
Note: If the SG detects loss of the M2UA peer (M2UA heartbeat loss or Note: If the SG detects loss of the M2UA peer (M2UA heartbeat loss or
detection of SCTP failure), the initial SG-ASP1 ASP Inactive message detection of SCTP failure), the initial SG-ASP1 ASP Inactive message
exchange would not occur. exchange would not occur.
4.2.2 (1+1 Sparing, Back-up Over-ride) 5.2.2 (1+1 Sparing, Back-up Over-ride)
Following on from the example in Section 4.1.2, and ASP2 wishes to over- Following on from the example in Section 5.1.2, and ASP2 wishes to over-
ride ASP1 and take over the traffic: ride ASP1 and take over the traffic:
SG ASP1 ASP2 SG ASP1 ASP2
| | | | | |
|<------------------------------ ASP Active----------| |<------------------------------ ASP Active----------|
|-----------------------------NTFY(ASP-Active)------>| |-----------------------------ASP-Active Ack-------->|
|----NTFY(ASP-Inactive)-->| |----NTFY( Alt ASP-Act)-->|
| | | | | |
4.2.3 (n+k Sparing, Load-sharing case, withdrawal of ASP) 5.2.3 (n+k Sparing, Load-sharing case, withdrawal of ASP)
Following on from the example in Section 4.1.4, and ASP1 withdraws from Following on from the example in Section 5.1.4, and ASP1 withdraws from
service: service:
SG ASP1 ASP2 ASP3 SG ASP1 ASP2 ASP3
| | | | | | | |
|<----ASP Inact.-----| | | |<----ASP Inact.-----| | |
|--NTFY(ASP-Inact.)->| | | |---ASP-Inact Ack--->| | |
| | | | | | | |
|---------------------------------NTFY(Ins. ASPs)(Optional)->| |---------------------------------NTFY(Ins. ASPs)(Optional)->|
| | | | | | | |
|<-----------------------------------------ASP Act. (Ldshr)--| |<-----------------------------------------ASP Act (Ldshr)---|
|-------------------------------------------ASP Act. (Ack)-->| |-------------------------------------------ASP Act (Ack)--->|
| | | | | | | |
The Notify message to ASP3 is optional, as well as the ASP-Active from The Notify message to ASP3 is optional, as well as the ASP-Active from
ASP3. The optional Notify can only occur if the SG maintains knowledge ASP3. The optional Notify can only occur if the SG maintains knowledge
of the minimum ASP resources required - for example if the SG knows that of the minimum ASP resources required - for example if the SG knows that
˘n+k÷ = ˘2+1÷ for a loadshare AS and ˘n÷ currently equals ˘1÷. ˘n+k÷ = ˘2+1÷ for a loadshare AS and ˘n÷ currently equals ˘1÷.
Note: If the SG detects loss of the ASP1 M2UA peer (M2UA heartbeat loss Note: If the SG detects loss of the ASP1 M2UA peer (M2UA heartbeat loss
or detection of SCTP failure), the first SG-ASP1 ASP Inactive message or detection of SCTP failure), the first SG-ASP1 ASP Inactive message
exchange would not occur. exchange would not occur.
4.3 SG to MGC, MTP Level 2 to MTP Level 3 Boundary Procedures 5.3 SG to MGC, MTP Level 2 to MTP Level 3 Boundary Procedures
4.3.1 SS7 Link Alignment 5.3.1 SS7 Link Alignment
The MGC can request that a SS7 link be brought into alignment using the The MGC can request that a SS7 link be brought into alignment using the
normal or emergency procedure. An example of the message flow to bring normal or emergency procedure. An example of the message flow to bring
a SS7 link in-service using the normal alignment procedure is shown a SS7 link in-service using the normal alignment procedure is shown
below. below.
SG ASP SG ASP
| | | |
|<---------Establish Req--------------| |<---------Establish Req--------------|
| | | |
skipping to change at page 30, line 35 skipping to change at page 30, line 35
| | | |
|<----State Req (STATUS_EMER_SET)-----| |<----State Req (STATUS_EMER_SET)-----|
| | | |
|-----State Cfm (STATUS_EMER_SET)---->| |-----State Cfm (STATUS_EMER_SET)---->|
| | | |
|<---------Establish Req--------------| |<---------Establish Req--------------|
| | | |
|----------Establish Cfm------------->| |----------Establish Cfm------------->|
| | | |
4.3.2 SS7 Link Release 5.3.2 SS7 Link Release
The MGC can request that a SS7 link be taken out-of-service. It uses The MGC can request that a SS7 link be taken out-of-service. It uses
the Release Request message as shown below. the Release Request message as shown below.
SG ASP SG ASP
| | | |
|<-----Release Req (RELEASE_MGMT)-----| |<-----Release Req (RELEASE_MGMT)-----|
| | | |
|------------Release Cfm------------->| |------------Release Cfm------------->|
| | | |
The SG can autonomously indicate that a SS7 link has gone out-of-service The SG can autonomously indicate that a SS7 link has gone out-of-service
as shown below. as shown below.
SG ASP SG ASP
| | | |
|------Release Ind (RELEASE_PHYS)---->| |------Release Ind (RELEASE_PHYS)---->|
| | | |
4.3.3 Set and Clear Local Processor Outage 5.3.3 Set and Clear Local Processor Outage
The MGC can set a Local Processor Outage condition. It uses the The MGC can set a Local Processor Outage condition. It uses the
State Request message as shown below. State Request message as shown below.
SG ASP SG ASP
| | | |
|<-----State Req (STATUS_LPO_SET)-----| |<-----State Req (STATUS_LPO_SET)-----|
| | | |
|------State Cfm (STATUS_LPO_SET)---->| |------State Cfm (STATUS_LPO_SET)---->|
| | | |
skipping to change at page 30, line 77 skipping to change at page 30, line 77
The MGC can clear a Local Processor Outage condition. It uses the The MGC can clear a Local Processor Outage condition. It uses the
State Request message as shown below. State Request message as shown below.
SG ASP SG ASP
| | | |
|<----State Req (STATUS_LPO_CLEAR)----| |<----State Req (STATUS_LPO_CLEAR)----|
| | | |
|-----State Cfm (STATUS_LPO_CLEAR)--->| |-----State Cfm (STATUS_LPO_CLEAR)--->|
| | | |
4.3.4 Notification of Processor Outage (local or remote) 5.3.4 Notification of Processor Outage (local or remote)
The SG can indicate a Local or Remote Processor Outage condition. It The SG can indicate a Local or Remote Processor Outage condition. It
uses the State Indication message as shown below. uses the State Indication message as shown below.
SG ASP SG ASP
| | | |
|-----State Ind (EVENT_ENTER_LPO)---->| |-----State Ind (EVENT_ENTER_LPO)---->|
| | | |
|-----State Ind (EVENT_EXIT_LPO)----->| |-----State Ind (EVENT_EXIT_LPO)----->|
| | | |
SG ASP SG ASP
| | | |
|-----State Ind (EVENT_ENTER_RPO)---->| |-----State Ind (EVENT_ENTER_RPO)---->|
| | | |
|-----State Ind (EVENT_EXIT_RPO)----->| |-----State Ind (EVENT_EXIT_RPO)----->|
| | | |
4.3.5 SS7 Link Changeover 5.3.5 SS7 Link Changeover
An example of the message flow for a changeover is shown below. In this An example of the message flow for a changeover is shown below. In this
example, there were three messages in the retransmission queue that example, there were three messages in the retransmission queue that
needed to be retrieved. needed to be retrieved.
SG ASP SG ASP
| | | |
|----Retrieval Req (MTP2_RTRV_BSN)--->| |<---Retrieval Req (MTP2_RTRV_BSN)----|
| | | |
|------Retrieval Cfm (with BSN)------>| |------Retrieval Cfm (with BSN)------>|
| | | |
|---Retrieval Req (MTP2_RTRV_MSGS)--->| |<--Retrieval Req (MTP2_RTRV_MSGS)----|
| with FSN | | with FSN |
| | | |
|-----------Retrieval Cfm------------>| |-----------Retrieval Cfm------------>|
| | | |
|-----------Retrieval Ind------------>| |-----------Retrieval Ind------------>|
|-----------Retrieval Ind------------>| |-----------Retrieval Ind------------>|
|-------Retrieval Complete Ind------->| |-------Retrieval Complete Ind------->|
| | | |
Note: The number of Retrieval Indication is dependent on the number of Note: The number of Retrieval Indication is dependent on the number of
messages in the retransmit queue that have been requested. Only one messages in the retransmit queue that have been requested. Only one
Retrieval Complete Indication should be sent. Retrieval Complete Indication should be sent.
5.0 Security 6.0 Security
5.1 Introduction 6.1 Introduction
M2UA is designed to carry signaling messages for telephony services. As such, M2UA is designed to carry signaling messages for telephony services. As such,
M2UA must involve the security needs of several parties: the end users M2UA must involve the security needs of several parties: the end users
of the services; the network providers and the applications involved. of the services; the network providers and the applications involved.
Additional requirements may come from local regulation. While having some Additional requirements may come from local regulation. While having some
overlapping security needs, any security solution should fulfill all of the overlapping security needs, any security solution should fulfill all of the
different parties' needs. different parties' needs.
5.2 Threats 6.2 Threats
There is no quick fix, one-size-fits-all solution for security. As a There is no quick fix, one-size-fits-all solution for security. As a
transport protocol, M2UA has the following security objectives: transport protocol, M2UA has the following security objectives:
* Availability of reliable and timely user data transport. * Availability of reliable and timely user data transport.
* Integrity of user data transport. * Integrity of user data transport.
* Confidentiality of user data. * Confidentiality of user data.
M2UA runs on top of SCTP. SCTP [6] provides certain transport related M2UA runs on top of SCTP. SCTP [6] provides certain transport related
security features, such as: security features, such as:
skipping to change at page 32, line 11 skipping to change at page 32, line 11
provider network, it is reasonable to expect that this network includes provider network, it is reasonable to expect that this network includes
an appropriate security policy framework. The "Site Security Handbook" [9] an appropriate security policy framework. The "Site Security Handbook" [9]
should be consulted for guidance. should be consulted for guidance.
When the network in which M2UA runs in involves more than one party, it When the network in which M2UA runs in involves more than one party, it
may not be reasonable to expect that all parties have implemented security may not be reasonable to expect that all parties have implemented security
in a sufficient manner. In such a case, it is recommended that IPSEC is in a sufficient manner. In such a case, it is recommended that IPSEC is
used to ensure confidentiality of user payload. Consult [10] for more used to ensure confidentiality of user payload. Consult [10] for more
information on configuring IPSEC services. information on configuring IPSEC services.
5.3 Protecting Confidentiality 6.3 Protecting Confidentiality
Particularly for mobile users, the requirement for confidentiality may Particularly for mobile users, the requirement for confidentiality may
include the masking of IP addresses and ports. In this case application include the masking of IP addresses and ports. In this case application
level encryption is not sufficient; IPSEC ESP should be used instead. level encryption is not sufficient; IPSEC ESP should be used instead.
Regardless of which level performs the encryption, the IPSEC ISAKMP Regardless of which level performs the encryption, the IPSEC ISAKMP
service should be used for key management. service should be used for key management.
6.0 IANA Considerations 7.0 IANA Considerations
A request will be made to IANA to assign an M2UA value for the Payload A request will be made to IANA to assign an M2UA value for the Payload
Protocol Identifier in SCTP Payload Data chunk. The following SCTP Payload Protocol Identifier in SCTP Payload Data chunk. The following SCTP Payload
Protocol Identifier will be registered: Protocol Identifier will be registered:
M2UA tbd M2UA tbd
The SCTP Payload Protocol Identifier is included in each SCTP Data chunk, The SCTP Payload Protocol Identifier is included in each SCTP Data chunk,
to indicate which protocol the SCTP is carrying. This Payload Protocol to indicate which protocol the SCTP is carrying. This Payload Protocol
Identifier is not directly used by SCTP but may be used by certain network Identifier is not directly used by SCTP but may be used by certain network
entities to identify the type of information being carried in a Data chunk. entities to identify the type of information being carried in a Data chunk.
The User Adaptation peer may use the Payload Protocol Identifier as a way The User Adaptation peer may use the Payload Protocol Identifier as a way
of determining additional information about the data being presented to it of determining additional information about the data being presented to it
by SCTP. by SCTP.
7.0 Acknowledgements 8.0 Acknowledgements
The authors would like to thank Ian Rytina, Hanns Juergen Schwarzbauer The authors would like to thank Ian Rytina, Hanns Juergen Schwarzbauer
and ZhangYi for their valuable comments and suggestions. and ZhangYi for their valuable comments and suggestions.
8.0 References 9.0 References
[1] ITU-T Recommendation Q.700, 'Introduction To ITU-T Signalling [1] ITU-T Recommendation Q.700, 'Introduction To ITU-T Signalling
System No. 7 (SS7)' System No. 7 (SS7)'
[2] ITU-T Recommendation Q.701-Q.705, 'Signalling System No. 7 (SS7) - [2] ITU-T Recommendation Q.701-Q.705, 'Signalling System No. 7 (SS7) -
Message Transfer Part (MTP)' Message Transfer Part (MTP)'
[3] ANSI T1.111 'Signalling System Number 7 - Message Transfer Part' [3] ANSI T1.111 'Signalling System Number 7 - Message Transfer Part'
[4] Bellcore GR-246-CORE 'Bell Communications Research Specification [4] Bellcore GR-246-CORE 'Bell Communications Research Specification
skipping to change at line 1841 skipping to change at line 2056
[8] ITU-T Recommendation Q.2210, 'Message transfer part level 3 [8] ITU-T Recommendation Q.2210, 'Message transfer part level 3
functions and messages using the services of ITU-T functions and messages using the services of ITU-T
Recommendation Q.2140' Recommendation Q.2140'
[9] RFC 2196, "Site Security Handbook", B. Fraser Ed., September 1997 [9] RFC 2196, "Site Security Handbook", B. Fraser Ed., September 1997
[10] RFC 2401, "Security Architecture for the Internet Protocol", S. [10] RFC 2401, "Security Architecture for the Internet Protocol", S.
Kent, R. Atkinson, November 1998. Kent, R. Atkinson, November 1998.
9.0 Author's Addresses 10.0 Author's Addresses
Ken Morneault Tel: +1-703-484-3323 Ken Morneault Tel: +1-703-484-3323
Cisco Systems Inc. EMail: kmorneau@cisco.com Cisco Systems Inc. EMail: kmorneau@cisco.com
13615 Dulles Technology Drive 13615 Dulles Technology Drive
Herndon, VA. 20171 Herndon, VA. 20171
USA USA
Malleswar Kalla Tel: +1-973-829-5212 Malleswar Kalla Tel: +1-973-829-5212
Telcordia Technologies EMail: kalla@research.telcordia.com Telcordia Technologies EMail: kalla@research.telcordia.com
MCC 1J211R MCC 1J211R
skipping to change at line 1874 skipping to change at line 2089
1651 North Glenville, Suite 216 1651 North Glenville, Suite 216
Richardson, TX 75081 Richardson, TX 75081
USA USA
Tom George Tel: +1-972-519-3168 Tom George Tel: +1-972-519-3168
Alcatel USA EMail: tom.george@usa.alcatel.com Alcatel USA EMail: tom.george@usa.alcatel.com
1000 Coit Road 1000 Coit Road
Plano, TX 74075 Plano, TX 74075
USA USA
This Internet Draft expires September 2000. This Internet Draft expires December 2000.
 End of changes. 

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