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Time To Live (TTL) Processing in Multi-Protocol Label Switching (MPLS) Networks (RFC3443)

IP.com Disclosure Number: IPCOM000011186D
Original Publication Date: 2003-Jan-01
Included in the Prior Art Database: 2003-Feb-13
Document File: 11 page(s) / 19K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

P. Agarwal: AUTHOR [+2]

Abstract

This document describes Time To Live (TTL) processing in hierarchical Multi-Protocol Label Switching (MPLS) networks and is motivated by the need to formalize a TTL-transparent mode of operation for an MPLS label-switched path. It updates RFC 3032, "MPLS Label Stack Encoding". TTL processing in both Pipe and Uniform Model hierarchical tunnels are specified with examples for both "push" and "pop" cases. The document also complements RFC 3270, "MPLS Support of Differentiated Services" and ties together the terminology introduced in that document with TTL processing in hierarchical MPLS networks.

This text was extracted from an ASCII text file.
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Network Working Group                                         P. Agarwal

Request for Comments: 3443                                       Brocade

Updates: 3032                                                   B. Akyol

Category: Standards Track                                  Cisco Systems

                                                            January 2003

                   Time To Live (TTL) Processing in

             Multi-Protocol Label Switching (MPLS) Networks

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 Internet Society (2003).  All Rights Reserved.

Abstract

   This document describes Time To Live (TTL) processing in hierarchical

   Multi-Protocol Label Switching (MPLS) networks and is motivated by

   the need to formalize a TTL-transparent mode of operation for an MPLS

   label-switched path.  It updates RFC 3032, "MPLS Label Stack

   Encoding".  TTL processing in both Pipe and Uniform Model

   hierarchical tunnels are specified with examples for both "push" and

   "pop" cases.  The document also complements RFC 3270, "MPLS Support

   of Differentiated Services" and ties together the terminology

   introduced in that document with TTL processing in hierarchical MPLS

   networks.

Conventions used in this document

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",

   "SHOULD", "SHOULD NOT", "RECOMMENDED",  "MAY", and "OPTIONAL" in this

   document are to be interpreted as described in [RFC-2119].

1. Introduction and Motivation

   This document describes Time To Live (TTL) processing in hierarchical

   MPLS networks.  We believe that this document adds details that have

   not been addressed in [MPLS-ARCH, MPLS-ENCAPS], and that the methods

   presented in this document complement [MPLS-DS].

Agarwal & Akyol             Standards Track                     [Page 1]

RFC 3443            TTL Processing in MPLS Networks         January 2003

   In particular, a new mode of operation (referred to as the Pipe

   Model) is introduced to support the practice of configuring MPLS LSPs

   such that packets transiting the LSP see the tunnel as a single hop

   regardless of the number of intermediary label switch routers (LSR).

   The Pipe Model for TTL is currently being used in multiple networks

   and is provided as an option configurable by the network...