Generalized MPLS (GMPLS) RSVP-TE Signaling Extensions in Support of Calls
RFC 4974

Network Working Group                                   D. Papadimitriou
Request for Comments: 4974                                       Alcatel
Updates: 3473                                                  A. Farrel
Category: Standards Track                             Old Dog Consulting
                                                             August 2007

         Generalized MPLS (GMPLS) RSVP-TE Signaling Extensions
                          in Support of Calls

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 IETF Trust (2007).

Abstract

   In certain networking topologies, it may be advantageous to maintain
   associations between endpoints and key transit points to support an
   instance of a service.  Such associations are known as Calls.

   A Call does not provide the actual connectivity for transmitting user
   traffic, but only builds a relationship by which subsequent
   Connections may be made.  In Generalized MPLS (GMPLS) such
   Connections are known as Label Switched Paths (LSPs).

   This document specifies how GMPLS Resource Reservation Protocol -
   Traffic Engineering (RSVP-TE) signaling may be used and extended to
   support Calls.  These mechanisms provide full and logical
   Call/Connection separation.

   The mechanisms proposed in this document are applicable to any
   environment (including multi-area), and for any type of interface:
   packet, layer-2, time-division multiplexed, lambda, or fiber
   switching.

Papadimitriou & Farrel      Standards Track                     [Page 1]
RFC 4974           GMPLS RSVP-TE Signaling Extensions        August 2007

Table of Contents

   1. Introduction ....................................................3
      1.1. Applicability to ASON ......................................4
   2. Conventions Used in This document ...............................4
   3. Requirements ....................................................4
      3.1. Basic Call Function ........................................4
      3.2. Call/Connection Separation .................................5
      3.3. Call Segments ..............................................5
   4. Concepts and Terms ..............................................5
      4.1. What Is a Call? ............................................5
      4.2. A Hierarchy of Calls, Connections, Tunnels, and LSPs .......6
      4.3. Exchanging Access Link Capabilities ........................6
           4.3.1. Network-Initiated Calls .............................7
           4.3.2. User-Initiated Calls ................................7
           4.3.3. Utilizing Call Setup ................................8
   5. Protocol Extensions for Calls and Connections ...................8
      5.1. Call Setup and Teardown ....................................8
      5.2. Call Identification ........................................9
           5.2.1. Long Form Call Identification .......................9
           5.2.2. Short Form Call Identification ......................9
           5.2.3. Short Form Call ID Encoding ........................10
      5.3. LINK_CAPABILITY Object ....................................11
      5.4. Revised Message Formats ...................................12
           5.4.1. Notify Message .....................................12
      5.5. ADMIN_STATUS Object .......................................13
   6. Procedures in Support of Calls and Connections .................14
      6.1. Call/Connection Setup Procedures ..........................14
      6.2. Call Setup ................................................14
           6.2.1. Accepting Call Setup ...............................16
           6.2.2. Call Setup Failure and Rejection ...................16
      6.3. Adding a Connections to a Call ............................17
           6.3.1. Adding a Reverse Direction LSP to a Call ...........18
      6.4. Call-Free Connection Setup ................................18
      6.5. Call Collision ............................................18
      6.6. Call/Connection Teardown ..................................19
           6.6.1. Removal of a Connection from a Call ................20
           6.6.2. Removal of the Last Connection from a Call .........20
           6.6.3. Teardown of an "Empty" Call ........................20
           6.6.4. Attempted Teardown of a Call with Existing
                  Connections ........................................20