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Applicability Statement for CR-LDP (RFC3213)

IP.com Disclosure Number: IPCOM000006862D
Original Publication Date: 2002-Jan-01
Included in the Prior Art Database: 2002-Feb-07
Document File: 8 page(s) / 15K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

J. Ash: AUTHOR [+5]

Abstract

This document discusses the applicability of Constraint-Based LSP Setup using LDP. It discusses possible network applications, extensions to Label Distribution Protocol (LDP) required to implement constraint-based routing, guidelines for deployment and known limitations of the protocol. This document is a prerequisite to advancing CR-LDP on the standards track.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 24% of the total text.

Network Working Group                                             J. Ash

Request for Comments: 3213                                          AT&T

Category: Informational                                        M. Girish

                                                           Atoga Systems

                                                                 E. Gray

                                                               Sandburst

                                                             B. Jamoussi

                                                               G. Wright

                                                   Nortel Networks Corp.

                                                            January 2002

                   Applicability Statement for CR-LDP

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 (2002).  All Rights Reserved.

Abstract

   This document discusses the applicability of Constraint-Based LSP

   Setup using LDP.  It discusses possible network applications,

   extensions to Label Distribution Protocol (LDP) required to implement

   constraint-based routing, guidelines for deployment and known

   limitations of the protocol.  This document is a prerequisite to

   advancing CR-LDP on the standards track.

1. Introduction

   As the Internet evolves, additional capabilities are required to

   ensure proper treatment of data [3], voice, video and other delay

   sensitive traffic [4].  MPLS enhances source routing and allows for

   certain techniques, used in circuit switching, in IP networks.  This

   permits a scalable approach to handling these diverse transmission

   requirements.  CR-LDP [1] is a simple, scalable, open, non-

   proprietary, traffic engineering signaling protocol for MPLS IP

   networks.

   CR-LDP provides mechanisms for establishing explicitly routed Label

   Switched Paths (LSPs).  These mechanisms are defined as extensions to

   LDP [2].  Because LDP is a peer-to-peer protocol based on the

Ash, et al                   Informational                      [Page 1]

RFC 3213           Applicability Statement for CR-LDP       January 2002

   establishment and maintenance of TCP sessions, the following natural

   benefits exist:

      CR-LDP messages are reliably delivered by the underlying TCP, and

      State information associated with explicitly routed LSPs does not

      require periodic refresh.

      CR-LDP messages are flow controlled (throttled) through TCP.

   CR-LDP is defined for the specific purpose of establishing and

   maintaining explicitly routed LSPs.  Additional optional capabilities

   included have minimal impact on system performance and requirements

   when not in use for a specific explicitly routed LSP.  Optional

   capabilities provide for negotiation of LSP services and traffic

   management parameters over and above best-effort packet delivery

   including bandwidth allocation, setup and holding priorities.  CR-LDP

   optionally allows these parameters to be dynamically modified without

   disruption of the operational (in-service) LSP [4].

   CR-LDP allows the specification of a set of parameters to be signaled

   along with the LSP setup request.  Moreover, the network can be

   provisioned with a set of edge traffic conditioning functions (which

   could include marking, metering, policing and shaping).  This set of

   parameters along with the specification of edge conditioning

   functions can be shown to be adequate and powerful enough to

   describe, characterize and parameterize a wide variety of QoS

   scenarios and services including IP d...