Subject: RE: Unnumbered links in non-GMPLS scenario

From: "Naidu, Venkata" <[email-masked]>
Date: Mon, 11 Feb 2002 10:04:11 -0500

Senthil:

-> Unfortunately remote nodes won't be able to know the mapping if
-> it is only statically configured.

  Why not? GMPLS OSPF extensions floods all this info for 
  each and every link.

  You may want to look at:
http://www.ietf.org/internet-drafts/draft-ietf-ccamp-ospf-gmpls-extensions-0
4.txt
  Sub TLV types 11 and 12.

   	Specifically, when an LSR advertises an unnumbered TE link, 
      the advertisement carries both the local and the remote 
      identifiers of the link.  If the LSR doesn't know the remote 
      identifier of that link, the LSR should use a value of 0 as
      the remote identifier.

  So the second case - "doesn't know the remote identifier of that
  link" never happens if you know the remote IF_ID statically.

  *Learning* and "mapping" can either be static or dynamic. 
  Doesn't matter! Finally routing (or some other) protocol floods
  these mappings all over the network/area.

Venkata Naidu

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From: senthil venkatachalam <[email-masked]>
Date: Mon, 11 Feb 2002 20:27:50 -0500

Venkata,

If the vendor/carrier is willing to use static mapping and flood out the
mapping using the GMPLS extn to OSPF, then there isn't any issue w.r.t.
support for multiple unnumbered intfs.

But, the way I read the question, it sounded like he/she didn't want to run
GMPLS,
but still needed to be able to support unnumbered interfaces for MPLS.
In this case, there is no LMP, no GMPLS extns, only katz-yeung/li-schmidt extns.

Here manual configuration is ok for the local routers sharing multiple
unnumbered interfaces,
but there is no mechanism to flood out this mapping to remote nodes.

This is due to the implicit (and unstated) requirement that some subset
of GMPLS extensions be used to support unnumbered interfaces
(even for "regular" MPLS).

Regards
Senthil.

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From: Nabil Seddigh <[email-masked]>
Date: Thu, 14 Feb 2002 17:58:45 -0500

Probably that should be:

http://www.ietf.org/internet-drafts/draft-ietf-ccamp-gmpls-routing-01.txt

Best,
Nabil