Subject: [Isis-wg] Draft-ietf-isis-layer2-04: New PDUs

From: "Fedyk, Donald (Don)" <[email-masked]>
Date: Fri, 23 Apr 2010 08:30:39 -0500

Hi

Going through the document there are 3 PDUs associated with MGROUP and 3 for New TRILL Hello PDUs.  (6 out of budget of 8.)

Was Sub Typing of the PDUs considered?  It would seem prudent to only consume one PDU type per function.

Also MGROUP PDUs are really Topology Independent PDUs? Perhaps a name that reflects that fact would be better for the future.

Same goes for TRILL One new Hello Variant should be it and then sub type it?

Burning 6 new PDUs seems like over kill to me.

Don

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From: Donald Eastlake <[email-masked]>
Date: Fri, 23 Apr 2010 17:28:17 -0400

Hi,

On Fri, Apr 23, 2010 at 9:30 AM, Fedyk, Donald (Don) <
[email-masked]> wrote:

>  Hi
>
> Going through the document there are 3 PDUs associated with MGROUP and 3
> for New TRILL Hello PDUs.  (6 out of budget of 8.)
>
>  Also MGROUP PDUs are really Topology Independent PDUs? Perhaps a name
> that reflects that fact would be better for the future.
>

It was my impression that the MGROUP PDU was intended for data which not
only did not affect the topology but was also more variable, i.e., multicast
listener state which may be controlled by application level software. I
don't care much what the name of the PDU is. I suppose the MGROUP LSP,
MGROUP CSNP, and MGROUP PSNP could be done by sub-typing one PDU # but it
seems more natural to parallel the existing LSP/CSNP/PSNP structure.

> Same goes for TRILL One new Hello Variant should be it and then sub type

I do not consider the MTU-probe and MTU-ack to actually be limited to TRILL.
They and the MTU sub-TLV of the Extended reachability TLV could also be used
at Layer 3 for example, if someone wished to do so. Although it seems
slightly more consistent with the IS-IS PDUs allocated in the past to have
MTU-probe and MTU-ack be different PDUs, I would not have a problem with
using only one PDU # for both probe and ack and sub-typing.

The TRILL Hello is a different matter and I think it should be a separate
PDU.

> Don

Thanks,
Donald
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