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Re: Remote LFA path length to PQ : draft-shen-mpls-ldp-nnhop-label

Hannes Gredler <hannes@juniper.net> Mon, 05 August 2013 07:48 UTC

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Subject: Re: Remote LFA path length to PQ : draft-shen-mpls-ldp-nnhop-label
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From: Hannes Gredler <hannes@juniper.net>
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Date: Mon, 05 Aug 2013 09:47:54 +0200
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FWIW i agree to stephane's assertion. - SR provides us a session-less
indication what the PQ->Dest SPT Transport label will be, such
that implementations does not need to bring up dynamic T-LDP sessions.

furthermore with SR there is no topologic assumption how far a
PQ node may be located.

/hannes

On Aug 3, 2013, at 9:08 PM, <stephane.litkowski@orange.com> wrote:

> IMHO, it would not be a good idea to mix two different mechanism with remote LFA (establishing TLDP session or using nnhop label) as it may complexify the code. Moreover using nnhop label, we could imagine some situation where first the PQ is two hops way leading the PLR to request NNHOP label and then due to an event (metric change ?), the path to the PQ becomes 3 or 4 hops away. This kind of situation would be hard to manage, so I would propose as simplicity to keep TLDP.


> Moreover implementing segment routing procedures would permit to avoid TLDP sessions in a near future as described in STATUS BOF.
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

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