[CCAMP] Final Text ITU-T Liaison flexi-grid // Was: Draft Text for ITU-T - CCAMP Liason regarding Flexi-grid

[Ramon Casellas <[e-mail]>]

All,

As Deborah mentioned, the text of the liaison should be ready by now. 
Accommodating most (all?) comments by now, I would say the following 
seems to be quite final.

Chairs, could you please proceed? many thanks in advance

Regards,
Ramon

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In order to progress our work on the draft “Framework and Requirements 
for GMPLS based control of Flexi-grid DWDM networks” [1] and subsequent 
solution documents within the IETF CCAMP working group, we would like to 
receive your comments/clarification on the following items (addressing 
ITU-T experts within Q6, Q12 and Q14):

· Please comment on future changes regarding the values of nominal 
central frequency (NCF) granularity [NCFG, currently 6.25 GHz] and slot 
width granularity [currently 12.5 GHz], as defined in G.694.1. Is ITU-T 
considering alternative values (e.g. 3.125 GHz) for NCFG in the 
foreseeable future? If yes, is it correct to assume, that the following 
always holds, w.r.t. slot width granularity and NCF granularity?
SWG = 2 * NCFG [Note: changes in these values may require additional 
code-points within encodings at control plane protocols.]

· Clarification on the maximum values of the slot width (m parameter) 
and the expected use cases (e.g. to cover the whole C band).
[Note: Knowing these values is required since it has an impact on their 
encoding.]

· Opinion / Clarification on the data plane “hitless” and “hitless” 
capabilities. Is ITU-T considering any hitless procedure, such as 
resizing / restoration of a network media channel (in terms of its 
frequency slot)? Examples of cases where hitless capabilities may be 
considered are:

o   Case 1: Recovery where the new network media channel uses a diverse path
o   Case 2: shrink / enlarge frequency slot width, invariant NCF (n)
o   Case 3: shift the NCF (n), maintaining the frequency slot width (m)


· Clarification on the case where an OTUCn is carried by a (co-routed) 
group of network media channels which must be managed as a single entity 
(including set up, recovery, and hardware cross-connection). If this is 
in scope, what is the estimated availability of ITU-T Recommendation 
covering this new requirement?
[Note: CCAMP has considered so far the following requirement: “The 
control plane architecture SHOULD allow multiple media channels to be 
logically associated.  The control plane SHOULD allow the co-routing of 
a set of media channels logically associated”. If ITU-T covers this new 
requirement, it may have an impact on the control plane representation 
and related procedures.]

· G.872 defines that a media channel may carry more than one OCh-P 
signal. It also defines that a network media channel is the end-to-end 
channel allocated to transport a single OCh-P.  We would appreciate 
clarification on the application of network media channel with respect 
to media channel related to management and configuration aspects.

[1] http://tools.ietf.org/html/draft-ietf-ccamp-flexi-grid-fwk-01