Transition Scenarios for 3GPP Networks
RFC 3574

Network Working Group                                   J. Soininen, Ed.
Request for Comments: 3574                                         Nokia
Category: Informational                                      August 2003

                Transition Scenarios for 3GPP Networks

Status of this Memo

   This memo provides information for the Internet community.  It does
   not specify an Internet standard of any kind.  Distribution of this
   memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2003).  All Rights Reserved.

Abstract

   This document describes different scenarios in Third Generation
   Partnership Project (3GPP) defined packet network, i.e., General
   Packet Radio Service (GPRS) that would need IP version 6 and IP
   version 4 transition.  The focus of this document is on the scenarios
   where the User Equipment (UE) connects to nodes in other networks,
   e.g., in the Internet.  GPRS network internal transition scenarios,
   i.e., between different GPRS elements in the network, are out of
   scope.   The purpose of the document is to list the scenarios for
   further discussion and study.

Table of Contents

   1.  Introduction . . . . . . . . . . . . . . . . . . . . . . . . .  2
   2.  Scope of the Document. . . . . . . . . . . . . . . . . . . . .  2
   3.  Brief Description of the 3GPP Network Environment. . . . . . .  2
       3.1 GPRS Architecture Basics . . . . . . . . . . . . . . . . .  3
       3.2 IP Multimedia Core Network Subsystem (IMS) . . . . . . . .  3
   4.  Transition Scenarios . . . . . . . . . . . . . . . . . . . . .  5
       4.1 GPRS Scenarios . . . . . . . . . . . . . . . . . . . . . .  5
       4.2 IMS Scenarios  . . . . . . . . . . . . . . . . . . . . . .  8
   5.  Security Considerations. . . . . . . . . . . . . . . . . . . .  9
   6.  Contributing Authors . . . . . . . . . . . . . . . . . . . . . 10
   7.  Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 10
   8.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 10
       8.1.  Normative References . . . . . . . . . . . . . . . . . . 10
       8.2.  Informative References . . . . . . . . . . . . . . . . . 11
   9.  Editor's Address . . . . . . . . . . . . . . . . . . . . . . . 11
   10. Full Copyright Statement . . . . . . . . . . . . . . . . . . . 12

Soininen                     Informational                      [Page 1]
RFC 3574         Transition Scenarios for 3GPP Networks      August 2003

1.  Introduction

   This document describes the transition scenarios in 3GPP packet data
   networks that might come up in the deployment phase of IPv6.  The
   main purpose of this document is to identify and to document those
   scenarios for further discussion and study them in the v6ops working
   group.

   Just a brief overview of the 3GPP packet data network, GPRS, is given
   to help the reader to better understand the transition scenarios.  A
   better overview of the 3GPP specified GPRS can be found for example
   from [6].  The GPRS architecture is defined in [1].

2.  Scope of the Document

   The scope is to describe the possible transition scenarios in the
   3GPP defined GPRS network where a UE connects to, or is contacted
   from, the Internet or another UE.  The document describes scenarios
   with and without the usage of the SIP-based (Session Initiation
   Protocol [5]) IP Multimedia Core Network Subsystem (IMS).  The 3GPP
   releases 1999, 4, and 5 are considered as the basis.

   Out of scope are scenarios inside the GPRS network, i.e., on the
   different interfaces of the GPRS network.  This document neither
   changes 3GPP specifications, nor proposes changes to the current
   specifications.

   In addition, the possible transition scenarios are described.  The
   solutions will be documented in a separate document.

   All the possible scenarios are listed here.  Further analysis may
   show that some of the scenarios are not actually relevant in this
   context.

3.  Brief Description of the 3GPP Network Environment

   This section describes the most important concepts of the 3GPP
   environment for understanding the transition scenarios.  The first
   part of the description gives a brief overview to the GPRS network as
   such.  The second part concentrates on the IP Multimedia Core Network
   Subsystem (IMS).

Soininen                     Informational                      [Page 2]
RFC 3574         Transition Scenarios for 3GPP Networks      August 2003

3.1.  GPRS Architecture Basics

   This section gives an overview to the most important concepts of the
   3GPP packet architecture.  For more detailed description, please see
   [1].

   From the point of view of this document, the most relevant 3GPP