<TEWG> <Requirements for Multi-Area TE>

["Ash, Gerald R (Jerry)" <gash@att.com>]

NAME OF I-D:

 
http://www.ietf.org/internet-drafts/draft-ash-ccamp-multi-area-te-reqmts-00.
txt


SUMMARY:

  This draft describes requirements for multi-area TE.  Based on the
requirements, the goal is to eventually protocol extensions needed for
multi-area TE.  Various approaches to multi-area TE are considered, based on
the intra-area TE approaches discussed in the [te_framework] and
[te_qos_routing].  These TE approaches include time dependent routing (TDR)
LSP selection, state dependent routing (SDR) LSP selection, and event
dependent routing (EDR) LSP selection. We propose that the needed protocol
capability extensions (information exchange, etc.) should support the
various types of multi-area TE identified in the draft. The focus initially
is on multi-area TE, and not multi-AS TE.  IP over optical (IPO)
requirements are considered [mp-lambda-s, gmpls], including the unique
routing requirements of the optical plane.  Initial
requirements are given for protocol support of the various multi-area TE
methods, which include needs to support route-server (RS) functionality,
query functionality, crankback functionality, TE feedback functionality, and
summary-LSA functionality.

RELATED DOCUMENTS:

http://search.ietf.org/internet-drafts/draft-venkatachalam-ospf-traffic-01.t
xt
http://search.ietf.org/internet-drafts/draft-venkatachalam-interarea-mpls-te
-01.txt
http://search.ietf.org/internet-drafts/draft-dharanikota-interarea-mpls-te-e
xt-01.txt
http://search.ietf.org/internet-drafts/draft-lee-mpls-te-exchange-01.txt
http://search.ietf.org/internet-drafts/draft-lee-mpls-path-request-00.txt
http://www.ietf.org/internet-drafts/draft-iwata-mpls-crankback-00.txt
http://search.ietf.org/internet-drafts/draft-kompella-mpls-multiarea-te-01.t
xt
http://search.ietf.org/internet-drafts/draft-bernstein-optical-bgp-00.txt
http://search.ietf.org/internet-drafts/draft-parent-obgp-01.txt

WHERE DOES IT FIT IN THE PICTURE OF THE SUB-IP WORK:

It fits in the TE-WG.  In particular, it fits within the TEWG Requirements
Design Team effort since it already contains requirements for multi-area TE.


WHY IS IT TARGETED AT THIS WG:

The work is intended to provide service provider (SP) requirements for
multi-area TE.  At the IETF-50 TEWG meeting, Scott Bradner initiated a
"Hierarchy Design Team", and on 5/13/2001, Bert Wijnen and Scott Bradner
re-initiated a combined network-hierarchy/survivability-techniques
Requirements Design Team, where this work still fits in.

JUSTIFICATION:

1. RFC2329 makes it clear that a hierarchy may be needed to accommodate
large networks.
2. TE information carried in Opaque LSAs needs to carefully considered
because of the amount of traffic they generate (even in the normal state of
network conditions).
3. The concepts to be adopted for inter-area-TE may have significant
differences from intra-area routing.