Subject: Re: [mpls] Working group last call ondraft-ietf-mpls-tp-ring-protection

From: "Doolan, Paul (NSN - US/Irving)" <[email-masked]>
Date: Thu, 4 Oct 2012 07:36:54 +0800

Hi Loa,

I have re-read the draft in question. Please note also that I am a
colleague of one of the authors but made no contribution to it nor was
my input solicited by them.

This should be a no-brainer: the first sentence of the document says
"this is an applicability statement".  

If your question is "how do I protect MPLS-TP traffic in ring
topologies" this document says "you _could_  do it with the linear
protection mechanisms already defined in RFC6378 in the following way".
As such it clearly explains an extant problem and demonstrates a
solution to it using available tools already defined by this WG and -
presumably - available in implementations today. It may not be perfect,
it may have some limitations and there may be, at some later date,
another solution, but, even then, there will still be applications for
which this is a perfectly adequate and viable solution.

I have fielded questions and had discussions with operators which
clearly indicate to me that an RFC explaining this application of
MPLS-TP linear protection would be valuable to the community. 

Words, or more correctly their meanings, are important things. I do not
know whether the incorrectly spelt 'aleviates'  in one of the last
sentences of the draft was a very deliberate choice or a happy accident,
but in  that sentence - "This thereby aleviates the necessity to create
a new mechanism or protocol to support the protection of ring
topologies"  - the authors are not excluding development of other
solutions. They are, to use one definition of the word, simply making
the wait ('suffering' in Websters) more bearable. I hope that
clarification assuages at least one of the concerns expressed in other
responses to your call.

I support progressing this document.

best regards,
pd

Paul Doolan
NSN ON