RFC 3332 (rfc3332) - Page 3 of 120

Signaling System 7 (SS7) Message Transfer Part 3 (MTP3) - User Adaptation Layer (M3UA)

RFC 3332             SS7 MTP3-User Adaptation Layer       September 2002


1.  Introduction

   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 [17]. 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
   Gaway Controller (MGC) or  IP-resident Database [11], or between two
   IP-based applications.

1.1 Scope

   There is a need for Switched Circuit Network (SCN) signalling
   protocol delivery from an SS7 Signalling Gateway (SG) to a Media
   Gateway Controller (MGC) or IP-resident Database as described in the
   Framework Architecture for Signalling Transport [11].  The delivery
   mechanism should meet the following criteria:

   *  Support for the transfer of all SS7 MTP3-User Part messages (e.g.,
      ISUP [1,2,3], SCCP [4,5,6], TUP [12], etc.)
   *  Support for the seamless operation of MTP3-User protocol peers
   *  Support for the management of SCTP transport associations and
      traffic between an SG and one or more MGCs or IP-resident
      Databases
   *  Support for MGC or IP-resident Database process failover and load
      sharing
   *  Support for the asynchronous reporting of status changes to
      management

   In simplistic transport terms, the SG will terminate SS7 MTP2 and
   MTP3 protocol layers [7,8,9] and deliver ISUP, SCCP and/or any other
   MTP3-User protocol messages, as well as certain MTP network
   management events, over SCTP transport associations to MTP3-User
   peers in MGCs or IP-resident Databases.
















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