ISIS Extensions in Support of Inter-Autonomous System (AS) MPLS and GMPLS Traffic Engineering
RFC 5316
Network Working Group M. Chen
Request for Comments: 5316 R. Zhang
Category: Standards Track Huawei Technologies Co., Ltd
X. Duan
China Mobile
December 2008
ISIS Extensions in Support of Inter-Autonomous System (AS)
MPLS and GMPLS Traffic Engineering
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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Abstract
This document describes extensions to the ISIS (ISIS) protocol to
support Multiprotocol Label Switching (MPLS) and Generalized MPLS
(GMPLS) Traffic Engineering (TE) for multiple Autonomous Systems
(ASes). It defines ISIS-TE extensions for the flooding of TE
information about inter-AS links, which can be used to perform inter-
AS TE path computation.
No support for flooding information from within one AS to another AS
is proposed or defined in this document.
Chen, et al. Standards Track [Page 1]
RFC 5316 ISIS Extensions for Inter-AS TE December 2008
Table of Contents
1. Introduction ....................................................2
1.1. Conventions Used in This Document ..........................3
2. Problem Statement ...............................................3
2.1. A Note on Non-Objectives ...................................4
2.2. Per-Domain Path Determination ..............................4
2.3. Backward Recursive Path Computation ........................6
3. Extensions to ISIS-TE ...........................................7
3.1. Inter-AS Reachability TLV ..................................7
3.2. TE Router ID ...............................................9
3.3. Sub-TLV Detail .............................................9
3.3.1. Remote AS Number Sub-TLV ............................9
3.3.2. IPv4 Remote ASBR ID Sub-TLV ........................10
3.3.3. IPv6 Remote ASBR ID Sub-TLV ........................11
3.3.4. IPv4 TE Router ID sub-TLV ..........................11
3.3.5. IPv6 TE Router ID sub-TLV ..........................12
4. Procedure for Inter-AS TE Links ................................12
4.1. Origin of Proxied TE Information ..........................14
5. Security Considerations ........................................14
6. IANA Considerations ............................................15
6.1. Inter-AS Reachability TLV .................................15
6.2. Sub-TLVs for the Inter-AS Reachability TLV ................15
6.3. Sub-TLVs for the IS-IS Router Capability TLV ..............17
7. Acknowledgments ................................................17
8. References .....................................................17
8.1. Normative References ......................................17
8.2. Informative References ....................................17
1. Introduction
[ISIS-TE] defines extensions to the ISIS protocol [ISIS] to support
intra-area Traffic Engineering (TE). The extensions provide a way of
encoding the TE information for TE-enabled links within the network
(TE links) and flooding this information within an area. The
extended IS reachability TLV and traffic engineering router ID TLV,
which are defined in [ISIS-TE], are used to carry such TE
information. The extended IS reachability TLV has several nested
sub-TLVs that describe the TE attributes for a TE link.
[ISIS-TE-V3] and [GMPLS-TE] define similar extensions to ISIS [ISIS]
in support of IPv6 and GMPLS traffic engineering, respectively.
Requirements for establishing Multiprotocol Label Switching (MPLS) TE
Label Switched Paths (LSPs) that cross multiple Autonomous Systems
(ASes) are described in [INTER-AS-TE-REQ]. As described in [INTER-
AS-TE-REQ], a method SHOULD provide the ability to compute a path
spanning multiple ASes. So a path computation entity that may be the
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