Subject: RE: [Isis-wg] Re: [Fwd: [mpls] WG Last Call ondraft-ietf-mpls-number-0-bw-te-lsps-02.txt]

From: "Les Ginsberg \(ginsberg\)" <[email-masked]>
Date: Thu, 7 Dec 2006 17:46:37 -0800

JP -

Sorry for the very belated comments - but I do have two minor, but still
important, concerns regarding IS-IS.

Both are in Section 3.1.

1)You have specified a 32 bit value for the number of unconstrained TE
LSPs. I would prefer that this be a 16 bit value. This still provides
ample range and given the 255 octet limit for a TLV, it is worthwhile to
be prudent in our use of encoding space. And, unlike OSPF, there is no
benefit in IS-IS to attempts to align fields on a natural boundary.
Whether you want to change OSPF encoding to match is not required and is
left up to you and OSPF folks to decide.

So
     Length (1 octet): 4

becomes

     Length (1 octet): 2

And

   Value (4 octets): number of unconstrained TE LSP(s) signalled across
   the link.

Becomes

   Value (2 octets): number of unconstrained TE LSP(s) signalled across
   the link.

2)Remove the following sentence from the first paragraph of Section 3.1:

"If a second instance of the Number of
   0-bandwidth TE LSP(s) sub-TLV is present, the receiving system MUST
   only process the first instance of the sub-TLV."

In cases where a TLV may move from one LSP fragment to another (for
example because of the addition of information which exceeds the
carrying capacity of the original LSP fragment) a router may have
multiple copies of the same TLV as a transient condition. It is
impossible to know which of the copies is newer and therefore impossible
to deterministically decide which is the first instance of a subTLV. So
it is better to leave the behavior in this case as undefined.

Thanx - and once again my apologies for the very late review.

   Les

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From: JP Vasseur <[email-masked]>
Date: Thu, 7 Dec 2006 21:07:45 -0500

Hi Les,

Your comments definitely make sense, thanks. I'll respin a new  
revision very soon, this time the last one.

Thanks.

JP.