TE-WG draft-lee-mpls-te-exchange-01.txt

[Cheng-Yin Lee <leecy@paragon-networks.com>]

NAME OF I-D:
http://search.ietf.org/internet-drafts/draft-lee-mpls-te-exchange-01.txt

SUMMARY

This draft describes a scalable approach to disseminate Traffic
Engineering link states in a  single area or  multiple areas in OSPF,
for the purpose of setting up paths.  In a fully-meshed network of n
nodes, the reduction in TE link state flooded is from O(n^3) to O(n).
Given that TE link state changes eg changes in bandwidth on a link tends
to occur more frequently than topology changes, and the relatively
larger number of TE ink states, this reduction in flooding improves the
stability of the routing protocol, using less total network and routers
resources (in terms of bandwidth, link state processing, and routing
information
storage) than if the TE link states are flooded instead.
It is worth noting that reducing the frequency of flooding in
link state routing protocol tend to increase the number of futile
attempts at path signalling and CPU intensive path recomputation.

RELATED DOCUMENTS


http://www.ietf.org/internet-drafts/draft-ash-ccamp-multi-area-te-reqmts-00.txt
http://search.ietf.org/internet-drafts/draft-kompella-mpls-multiarea-te-01.txt
draft-dharanikota-interarea-mpls-te-ext-01.txt
draft-venkatachalam-interarea-mpls-te-00.txt
http://search.ietf.org/internet-drafts/draft-lee-mpls-path-request.txt
http://search.ietf.org/internet-drafts/draft-ietf-ospf-subset-flood-00.txt
http://search.ietf.org/internet-drafts/draft-ietf-ospf-ppp-flood-01.txt
draft-ietf-ospf-isis-flood-opt-01.txt
ftp://ftp.isi.edu/in-notes/rfc2973.txt
http://search.ietf.org/internet-drafts/draft-ietf-ospf-floodgates-01.txt

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

It fits in the TE-WG.

  Applications         +-------+  +-------+        (new) Hour glass
  that use CCAMP: \    | TE-WG |  | PPVPN |  ...           /
                   \   +-------+  +-------+               /
                    \     +----------------------+       /
                     \    |         CCAMP        |      /
                      \   |-----------+----------|     /
                      /   |   C       |    M   --|------ IGP LSA ext
                     /    | control   | measure  |     \
                    /     +----------------------+      \
  Technologies to  / +----+ +----+ +----+ +----+ +----+  \
  measure/control:/  |MPLS| |OPT | |RPR | |ATM | | FR |...\
                     +----+ +----+ +----+ +----+ +----+


WHY IS IT TARGETED AT THIS WG

>From the charter of TE-WG:
"The working group also serves as a general forum for discussing
improvements to IETF protocols to advance the traffic engineering
function. ."

The draft  improves the scalability of the TE function, in general.

JUSTIFICATION

There are numerous drafts and an rfc addressing flooding issues, some
addressing only issues related to parallel paths between two routers.
This
draft addresses the flooding problem in a network (including
parallel paths between two routers) for MPLS/TE path setup.

http://www.ietf.org/internet-drafts/draft-ash-ccamp-multi-area-te-reqmts-00.txt
describes initial requirements for protocol support of multi-area TE of
which a route server functionality such as the one described in this
draft is required.