Re: [Isis-wg] Request for WG adoption of draft-xu-isis-mpls-elc-00

Robert Raszuk <robert@raszuk.net> Thu, 05 June 2014 14:07 UTC

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From: Robert Raszuk <robert@raszuk.net>
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Subject: Re: [Isis-wg] Request for WG adoption of draft-xu-isis-mpls-elc-00
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> As far as I understand your proposal, you need to create forwarding entries "per flow" in all nodes, that's creating more states ...
> Moreover, SIDs are bound to links and prefixes (not really node), so for Prefix SID, it's quite similar to a FEC , except that you can bind multiple SIDs to the same prefix. But each Prefix SID you are adding, adds a new forwarding state in the whole IGP domain.

No not at all :)

SIDs can be aggregated in forwarding just fine. Think v6 address for
simplicity .. or MPLS labels if your data plane supports such
aggregation ..

Then what is in the packet's header  is only input for today's hash function.

If there is any logic (and that does not need to be stateful) it is
only on ingress to impose packets with the proper IP/MPLS header.
That's it.

Last sure you have prefix SIDs but those prefixes just describe node
say loopbacks as example. Frankly I do not understand why this forced
indirection is really needed - but this is different topic.

Best,
R.