[Pce] comments on draft-ietf-pce-pcecp-interarea-reqs-00.txt

dimitri papadimitriou <dpapadimitriou@psg.com> Mon, 13 February 2006 16:10 UTC

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Date: Mon, 13 Feb 2006 17:10:56 +0100
From: dimitri papadimitriou <dpapadimitriou@psg.com>
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Subject: [Pce] comments on draft-ietf-pce-pcecp-interarea-reqs-00.txt
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folks,

the document mentions

   "A solution for computing inter-area TE-LSP path relies on a per
    domain path computation ([PD-COMP]). It is based on loose hop routing
    with an ERO expansion on each ABR. This can allow setting up a
    constrained path, but faces two major limitations:
         -This does not allow computing an optimal constrained path
         -This may lead to several signalling crankback messages and
          hence delay the LSP setup, and invoke routing activities. "

optimal computation does not imply resource reservation, hence a PCE
functionality does not prevent from crankback

section 5 present two models, would it be possible to consider that
homogeneity is not necessarily verified, e.g. an area having a single
ABR does not a PCE to reach the local exit point

section 7.13 should discuss scaling wrt to the TEDB wrt to single PCE
model it is stated that such consideration is beyond the scope of the
document i would more than certainly re-consider this since this a
necessary condition for supporting the "all area" PCE model (is this not
a single point of failure ? or are specifics in terms of resilience
outside the scope of this document)

thanks,
- dimitri.








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