Network Working Group                                     A. Farrel, Ed.
Request for Comments: 5420                            Old Dog Consulting
Obsoletes: 4420                                         D. Papadimitriou
Updates: 3209, 3473                                              Alcatel
Category: Standards Track                                    JP. Vasseur
                                                     Cisco Systems, Inc.
                                                             A. Ayyangar
                                                        Juniper Networks
                                                           February 2009


        Encoding of Attributes for MPLS LSP Establishment Using
      Resource Reservation Protocol Traffic Engineering (RSVP-TE)

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.

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   Copyright (c) 2009 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.



















Farrel, et al.              Standards Track                     [Page 1]

RFC 5420        Attributes for MPLS LSPs Using RSVP-TE     February 2009


Abstract

   Multiprotocol Label Switching (MPLS) Label Switched Paths (LSPs) may
   be established using the Resource Reservation Protocol Traffic
   Engineering (RSVP-TE) extensions.  This protocol includes an object
   (the SESSION_ATTRIBUTE object) that carries a Flags field used to
   indicate options and attributes of the LSP.  That Flags field has
   eight bits, allowing for eight options to be set.  Recent proposals
   in many documents that extend RSVP-TE have suggested uses for each of
   the previously unused bits.

   This document defines a new object for RSVP-TE messages that allows
   the signaling of further attribute bits and also the carriage of
   arbitrary attribute parameters to make RSVP-TE easily extensible to
   support new requirements.  Additionally, this document defines a way
   to record the attributes applied to the LSP on a hop-by-hop basis.

   The object mechanisms defined in this document are equally applicable
   to Generalized MPLS (GMPLS) Packet Switch Capable (PSC) LSPs and to
   GMPLS non-PSC LSPs.

   This document replaces and obsoletes the previous version of this
   work, published as RFC 4420.  The only change is in the encoding of
   the Type-Length-Variable (TLV) data structures.



























Farrel, et al.              Standards Track                     [Page 2]

RFC 5420        Attributes for MPLS LSPs Using RSVP-TE     February 2009


Table of Contents

   1. Introduction and Problem Statement ..............................4
      1.1. Applicability to Generalized MPLS ..........................5
      1.2. A Rejected Alternate Solution ..............................5
   2. Terminology .....................................................6
   3. Attributes TLVs .................................................6
      3.1. Attribute Flags TLV ........................................7
   4. LSP_ATTRIBUTES Object ...........................................8
      4.1. Format .....................................................9
      4.2. Generic Processing Rules for Path Messages .................9
      4.3. Generic Processing Rules for Resv Messages .................9
   5. LSP_REQUIRED_ATTRIBUTES Object .................................10
      5.1. Format ....................................................11