Subject: Re: [mpls-tp] working grouplastcallondraft-ietf-mpls-tp-requirements-08.txt

From: "Niven-jenkins,B,Ben,DMF R" <[email-masked]>
Date: Thu, 21 May 2009 09:43:53 +0100

The intent is surely to say MPLS-TP must support at least what SDH can but we're not limiting ourselves to the limits SDH has.

Ben

-----Original Message-----
From: "Alexander Vainshtein" <[email-masked]>
To: "Adrian Farrel" <[email-masked]>; "Weingarten, Yaacov (NSN - IL/Hod HaSharon)" <[email-masked]>
Cc: "[email-masked]" <[email-masked]>
Sent: 21/05/2009 08:38
Subject: Re: [mpls-tp] working grouplast	callondraft-ietf-mpls-tp-requirements-08.txt

Adrian, Yaakov and all,
On top of highly problematic English:
The original limit on up to 16 NEs in a SONET/SDH ring is a side effect of having just 4 bits for NE ID in the BLSR/MS-SPRing protocol
that used K1/K2 octets in the Line/MS overhead.

Unless we plan to reuse the same protocol in MPLS-TP or consider an upgrade of SONET/SDH muxes into MPLS-TP switches,
the limit of 16 MPLS-TP nodes in a ring looks artificial to me. 

My 2c,
     Sasha

> -----Original Message-----
> From: [email-masked] 
> [mailto:[email-masked]] On Behalf Of Adrian Farrel
> Sent: Wednesday, May 20, 2009 4:57 PM
> To: Weingarten, Yaacov (NSN - IL/Hod HaSharon)
> Cc: [email-masked]
> Subject: Re: [mpls-tp] working group last 
> callondraft-ietf-mpls-tp-requirements-08.txt
> 
> Yaacov,
> 
> > I have some comments on this document that can be seen more
> > as questions for clarification:
> > 
> > 1. Req 27-C: MPLS-TP MUST support rings of at least 16
> > nodes...MPLS-TP SHOULD support rings with more than
> > 16 nodes.
> > 
> > So is it a MUST or a SHOULD?  Isn't "at least 16" and "more
> > than 16" almost equivalent (except for exactly 16)?
> 
> Right 
> MUST support 0-16 
> SHOULD support 17...
> 
> That is what the text says.
> 
> > 2. In Req 100 & 102 - What is the difference between "Recovery
> > mechanisms" and "Recovery techniques"? Why is the first a MUST
> > and the second a SHOULD?
> 
> Good catch.
> Only one of the two requirements should remain.
> But which?
> 
> > Finally, just a little spelling note: in Req 32-A: change 
> "bellow" to
> > "below".
> 
> Cheers,
> Adrian
> 
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