Re: [CCAMP] Draft Text for ITU-T - CCAMP Liason regarding Flexi-grid

Ramon Casellas <> Wed, 19 March 2014 06:50 UTC

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Date: Wed, 19 Mar 2014 07:50:01 +0100
From: Ramon Casellas <>
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Subject: Re: [CCAMP] Draft Text for ITU-T - CCAMP Liason regarding Flexi-grid
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El 18/03/2014 22:52, Iftekhar Hussain escribió:
> Hi Ramon,
> "- A NMC as bound to 1 OCh-P by definition of the in-force G.872.
> - a Media channel may carry more than 1 OCh-P, but MC != NMC"
> The above looks fine and we have the same understanding. What needs 
> clarification is that (a) is NMC required? If so why?  Note that MC 
> already is a superset of NMC. The bullet didn't have whole text we 
> prefer the following full text in the liaison for clarity:
> "G.872 defines that a media channel may carry more than one OCh-P 
> signal. It also defines that a network media channel is a specific use 
> of media channel with a single OCh-P. Clarification is needed on the 
> definition and application of network media channel. If intent is that 
> there is always an end-to-end network media channel, then it should 
> support multiple OCh-Ps. Alternatively, eliminate the network media 
> channel definition altogether, in favor of always using the media 
> channel term which already supports this capability. Requiring a 
> one-to-one mapping between OCh-P and network media channels would be 
> restrictive in cases where multiple OCh-P need to go between the same 
> destinations. The most spectrally efficient packing of them may not 
> allow each OCh-P to use its own network media channel within the 
> defined flexible grid granularity"

Iftekhar, all

Following several comments received, your text was edited in past 
versions of the liaison draft. I would be ok to leave the text as is in 
the liaison if the working group agrees or does not object. However, I 
still wonder what kind of clarification/question do we need from the 
ITU-T (in such text), related the control plane protocol requirements 
and extensions.

Like Xian, I am also slightly afraid that the last bullet may be 
basically challenging the definition of the network media channel, 
something that is, IMHO, ITU-T business. Im am also reluctant to use a 
wording that seems to be issuing direct recommendations to ITU-T whether 
this or that term is required or whether this or that entity should 
support this or that capability or whether it would be too restrictive. 
That said, I may be completely wrong, and I am just editing :-)


Ramon Casellas, Ph.D. -- Senior Research Associate -- Networks Division
Optical Networks and Systems Department --
CTTC - Centre Tecnològic de Telecomunicacions de Catalunya
Parc Mediterrani de la Tecnologia (PMT) - Edifici B4
Av. Carl Friedrich Gauss, 7 - 08860 Castelldefels (Barcelona) - Spain
Tel.: +34 93 645 29 00 ext 2168-- Fax. +34 93 645 29 01