LSP Modification Using CR-LDP
RFC 3214
Network Working Group J. Ash
Request for Comments: 3214 AT&T
Category: Standards Track Y. Lee
Ceterus Networks
P. Ashwood-Smith
B. Jamoussi
D. Fedyk
D. Skalecki
Nortel Networks
L. Li
SS8 Networks
January 2002
LSP Modification Using CR-LDP
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 (2002). All Rights Reserved.
Abstract
This document presents an approach to modify the bandwidth and
possibly other parameters of an established CR-LSP (Constraint-based
Routed Label Switched Paths) using CR-LDP (Constraint-based Routed
Label Distribution Protocol) without service interruption. After a
CR-LSP is set up, its bandwidth reservation may need to be changed by
the network operator, due to the new requirements for the traffic
carried on that CR-LSP. The LSP modification feature can be
supported by CR-LDP by use of the _modify_value for the _action
indicator flag_ in the LSPID TLV. This feature has application in
dynamic network resources management where traffic of different
priorities and service classes is involved.
Ash, et al. Standards Track [Page 1]
RFC 3214 LSP Modification Using CR-LDP January 2002
Table of Contents
1. Conventions Used in This Document ............................ 2
2. Introduction ................................................. 2
3. LSP Modification Using CR-LDP ................................ 3
3.1 Basic Procedure for Resource Modification .................. 3
3.2 Rerouting LSPs ............................................. 5
3.3 Priority Handling .......................................... 6
3.4 Modification Failure Case Handling ......................... 6
4. Application of LSP Bandwidth Modification in Dynamic Resource
Management ................................................... 7
5. Acknowledgments .............................................. 8
6. Intellectual Property Considerations ......................... 8
7. Security Considerations ...................................... 8
8. References ................................................... 8
9. Authors' Addresses ........................................... 9
10. Full Copyright Statement ..................................... 11
1. Conventions Used in This Document
L: LSP (Label Switched Path)
L-id: LSPID (LSP Identifier)
T: Traffic Parameters
R: LSR (Label Switching Router)
FEC: Forwarding Equivalence Class
NHLFE: Next Hop Label Forwarding Entry
FTN: FEC To NHLFE
TLV: Type Length Value
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 [4].
2. Introduction
Consider an LSP L1 that has been established with its set of traffic
parameters T0. A certain amount of bandwidth is reserved along the
path of L1. Consider then that some changes are required on L1. For
example, the bandwidth of L1 needs to be increased to accommodate the
increased traffic on L1. Or the SLA associated with L1 needs to be
modified because a different service class is desired. The network
operator, in these cases, would like to modify the characteristics of
L1, for example, to change its traffic parameter set from T0 to T1,
without releasing the LSP L1 to interrupt the service. In some other
cases, network operators may want to reroute a CR-LSP to a different
path for either improved performance or better network resource
utilization. In all these cases, LSP modification is required. In
section 3 below, a method to modify an active LSP using CR-LDP is
Ash, et al. Standards Track [Page 2]
RFC 3214 LSP Modification Using CR-LDP January 2002
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