Network Working Group K. Morneault, Ed.
Request for Comments: 4666 Cisco Systems
Obsoletes: 3332 J. Pastor-Balbas, Ed.
Category: Standards Track Ericsson
September 2006
Signaling System 7 (SS7) Message Transfer Part 3 (MTP3) -
User Adaptation Layer (M3UA)
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2006).
Abstract
This memo defines a protocol for supporting the transport of any SS7
MTP3-User signalling (e.g., ISUP and SCCP messages) over IP using the
services of the Stream Control Transmission Protocol. Also,
provision is made for protocol elements that enable a seamless
operation of the MTP3-User peers in the SS7 and IP domains. This
protocol would be used between a Signalling Gateway (SG) and a Media
Gateway Controller (MGC) or IP-resident Database, or between two IP-
based applications. It is assumed that the SG receives SS7
signalling over a standard SS7 interface using the SS7 Message
Transfer Part (MTP) to provide transport. This document obsoletes
RFC 3332.
Morneault & Pastor-Balbas Standards Track [Page 1]
RFC 4666 SS7 MTP3-User Adaptation Layer September 2006
Table of Contents
1. Introduction ....................................................6
1.1. Scope ......................................................6
1.2. Terminology ................................................6
1.3. M3UA Overview ..............................................9
1.3.1. Protocol Architecture ...............................9
1.3.2. Services Provided by the M3UA Layer ................10
1.3.2.1. Support for the Transport of
MTP3-User Messages ........................10
1.3.2.2. Native Management Functions ...............11
1.3.2.3. Interworking with MTP3 Network
Management Functions ......................11
1.3.2.4. Support for the Management of SCTP
Associations between the ..................11
1.3.2.5. Support for the Management of
Connections to Multiple SGPs ..............12
1.4. Functional Areas ..........................................12
1.4.1. Signalling Point Code Representation ...............12
1.4.2. Routing Contexts and Routing Keys ..................14
1.4.2.1. Overview ..................................14
1.4.2.2. Routing Key Limitations ...................15
1.4.2.3. Managing Routing Contexts and
Routing Keys ..............................15
1.4.2.4. Message Distribution at the SGP ...........15
1.4.2.5. Message Distribution at the ASP ...........16
1.4.3. SS7 and M3UA Interworking ..........................16
1.4.3.1. Signalling Gateway SS7 Layers .............16
1.4.3.2. SS7 and M3UA Interworking at the SG .......17
1.4.3.3. Application Server ........................17
1.4.3.4. IPSP Considerations .......................18
1.4.4. Redundancy Models ..................................18
1.4.4.1. Application Server Redundancy .............18
1.4.5. Flow Control .......................................18
1.4.6. Congestion Management ..............................19
1.4.7. SCTP Stream Mapping ................................19
1.4.8. SCTP Client/Server Model ...........................19
1.5. Sample Configuration ......................................20
1.5.1. Example 1: ISUP Message Transport ..................20
1.5.2. Example 2: SCCP Transport between IPSPs ............21
1.5.3. Example 3: SGP Resident SCCP Layer, with
Remote ASP .........................................22
1.6. Definition of M3UA Boundaries .............................23
1.6.1. Definition of the Boundary between M3UA and
an MTP3-User .......................................23
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