RFC 3057 (rfc3057) - Page 2 of 66

ISDN Q

RFC 3057            ISDN Q.921-User Adaptation Layer       February 2001


Table of Contents

   1.  Introduction.................................................  2
     1.1  Scope.....................................................  2
     1.2  Terminology...............................................  3
     1.3  IUA Overview..............................................  4
     1.4  Services Provided by the IUA Layer........................  9
     1.5  Functions Implemented by the IUA Layer.................... 12
     1.6  Definition of IUA Boundaries.............................. 14
   2.  Conventions.................................................. 16
   3.  Protocol Elements............................................ 17
     3.1  Common Message Header..................................... 17
     3.2  IUA Message Header........................................ 20
     3.3  Description of Messages................................... 22
   4.  Procedures................................................... 45
     4.1  Procedures to Support Service in Section 1.4.1............ 45
     4.2  Procedures to Support Service in Section 1.4.2............ 46
     4.3  Procedures to Support Service in Section 1.4.3............ 47
   5. Examples...................................................... 56
     5.1 Establishment of associations between SG and MGC examples.. 56
     5.2 ASP Traffic Fail-over Examples............................. 58
     5.3 Q.921/Q.931 primitives backhaul Examples................... 59
     5.4 Layer Management Communication Examples.................... 61
   6.  Security..................................................... 61
     6.1 Threats.................................................... 61
     6.2 Protecting Confidentiality ................................ 62
   7.  IANA Considerations.......................................... 62
     7.1 SCTP Payload Protocol Identifier........................... 62
     7.2 IUA Protocol Extensions.................................... 62
   8.  Acknowledgements............................................. 64
   9.  References................................................... 64
   10. Authors' Addresses........................................... 65
   11. Full Copyright Statement..................................... 66

1.  Introduction

   In this document, the term Q.921-User refers to an upper layer which
   uses the services of Q.921, not the user side of ISDN interface [1].
   Examples of the upper layer would be Q.931 and QSIG.

   This section describes the need for ISDN Q.921-User Adaptation (IUA)
   layer protocol as well as how this protocol shall be implemented.

1.1 Scope

   There is a need for Switched Circuit Network (SCN) signaling protocol
   delivery from an ISDN Signaling Gateway (SG) to a Media Gateway
   Controller (MGC) as described in the Framework Architecture for



Morneault, et al.           Standards Track