Subject: review assignment: draft-ietf-mpls-explicit-null-01.txt: danny, mjh

From: Alex Zinin <[email-masked]>
Date: Fri, 27 Aug 2004 15:18:07 -0700

skill-specific: danny
round-robin: mark

http://www.ietf.org/internet-drafts/draft-ietf-mpls-explicit-null-01.txt

>         Removing a Restriction on the use of MPLS Explicit NULL

> Abstract
> 
>    The label stack encoding for MPLS (Multi-protocol Label Switching)
>    defines a reserved label value known as "IPv4 Explicit NULL" and a
>    reserved label value known as "IPv6 Explicit NULL".  Previously,
>    these labels were only legal when they occurred at the bottom of the
>    MPLS label stack.  This restriction is now removed, so that these
>    label values may legally occur anywhere in the stack.

-- 
Alex
http://www.psg.com/~zinin

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From: Danny McPherson <[email-masked]>
Date: Mon, 30 Aug 2004 14:17:13 -0600

> skill-specific: danny

Ack!

-danny

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From: Danny McPherson <[email-masked]>
Date: Fri, 3 Sep 2004 19:10:52 -0600

> http://www.ietf.org/internet-drafts/draft-ietf-mpls-explicit-null 

I just (re)read this document and it looks fine to me.  I believe
the general utility makes sense and it does remove over-restrictive
text that was specified in RFC 3032.  I also don't recall much
concern on the mailing list about this, and a terse review of the
discussions of this document suggests all outstanding comments have
been addressed by Eric.

The one comment that I have is that existing implementations may
interpret an Explicit NULL at a position other than the bottom
of the stack as illegal and invoke some error handling or discard
process.  The draft states that some implementations simply transmit
the illegal packet today and others "covert it to a legal packet" (by
stripping the Explicit NULL, thereby introducing the requirement for  
this
document).  As such, it may be of value to mention deployment
considerations explicitly somewhere in the document.

-danny