Subject: [Teas] Alia Atlas' No Objection on draft-ietf-teas-gmpls-resource-sharing-proc-08: (with COMMENT)

From: "Alia Atlas" <[email-masked]>
Date: Wed, 01 Feb 2017 21:39:27 -0800

Alia Atlas has entered the following ballot position for
draft-ietf-teas-gmpls-resource-sharing-proc-08: No Objection

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COMMENT:
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Thank you for a well-written and clear document.   I have one concern
around the assumptions in Sec 4.3.2.
If I have understood correctly,  the need to do Rollback will cause
traffic loss if resources were shared between
the restoration LSP and the reversion LSP.    Also, during
make-before-break, if there are shared resources, then
starting to set up the reversion LSP can cause the restoration LSP to
stop working.  It's possible that these traffic-impacting
aspects are well understood in the GMPLS world - but in the MPLS world,
they would be surprising side-effects.

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From: "Rakesh Gandhi (rgandhi)" <[email-masked]>
Date: Thu, 2 Feb 2017 18:41:40 +0000

Hi Alia,

Thank you for the review. Please see inline <RG> ..

On 2017-02-02, 12:39 AM, "Alia Atlas" <[email-masked]> wrote:

    

<RG> Yes, this is correct for GMPLS – non-packet transport networks and is covered in the following text in the draft:

4.2.  Resource Sharing-based Restoration LSP Setup

<snip>

   As described in [RFC3209], Section 2.5, the purpose of make-before-
   break is not to disrupt traffic, or adversely impact network
   operations while TE tunnel rerouting is in progress.  In non-packet
   transport networks during the RSVP-TE signaling procedure, the nodes
   set up cross-connections along the LSP accordingly.  Because the
   cross-connection cannot simultaneously connect a shared resource to
   different resources in two alternative LSPs, nodes may not be able to
   fulfill this request when LSPs share resources.

Does this help?

Thanks,
Rakesh