Subject: [CCAMP] FW: New Version Notification for draft-ogrcetal-ccamp-flexi-grid-fwk-03.txt

From: Oscar González de Dios <[email-masked]>
Date: Wed, 05 Jun 2013 19:22:19 +0000

Hi ccampers & flexi-griders,

During the last IETF we had a very profitable joint meeting with ITU-T
SG15 Q6 regarding flexi-grid. A set of questions with the doubts were
discussed and clarified. We have posted a new version of the Flexi-grid
framework reflecting the latest discussions and a general clean-up, which
you can find in
http://www.ietf.org/internet-drafts/draft-ogrcetal-ccamp-flexi-grid-fwk-03.
txt

 Please find bellow a summary of the answers to the questions and doubts
we had (the detailed minutes of the joint CCAMP-ITU-T meeting are already
posted on the IETF website), that are reflected in the new framework
document.

* Question 1.1 Relation between media layer and signal layer: which are
the allowed combinations?
--> There is only one possible combination: Single Optical Tributary
Signal (OTS) over Single Network media channel.
--> The term OTS relates to the entire signal (independently on how many
carriers it has) that gets put down in a network media channel. A
definition can be:     It is the light that goes through a network media
channel from TX to RX independently on the numbers of carriers.
There is no term yet defined to refer to the grouping of one or more OTS.
However, at some point in the future, it will be needed to consider
co-routing several network media channels (each of them that supports a
single OTS, which together will form a single data entity).

* Question 1.2. Do we need to consider express channel?
--> Although there is not really a true hierarchy in the media (spectrum),
from the management and control point of view, a hierarchy of media
channels is considered.

* Question 2.1.  What are the attributes of a link? Supported/Available
central frequencies  (N) Supported/Available slot width/granularity (M)
Portion of spectrum available, Are there other attributes that can¹t be
expressed via M and N? What are the attributes of a node? Connectivity
matrix?
--> All the attributes already available in the draft seem OK.

* Question 3. Regarding resource allocation, Are there different n,m
allowed along the path?
--> This aspect has not been debated in ITU, and there was no agreement.
It will be fixed in ITU-T G.872.

* Question 4. Is it envisioned to consider the impact of signal
characteristics on the link information? How it would be represented in
the control plane? :

--> In an environment of only pre-qualified paths, no. Otherwise,
impairment aware path computation issues as in WSON apply. Follow the work
in WSON.

Based on the previous answers, the premises of the framework for
flexi-grid networks are:
- The LSPs to be managed in flexi-grid are always media channels. If the
end-points are transceivers, they are (from ITU-T terminology) network
media channels.
- LSPs can be hierarchical (media channel over media channel).
- As LSPs are media channels, they are characterized by an n and m.
- The term super channel will no lo longer be used to avoid confusion.
>From now on, only Optical Tributary Signal is used.  The following
"mapping" from old terms to new terms is considered

-> A contiguous ³Superchannel² maps with one OTS.
-> Non-contiguous Superchannel maps to 2 or more OTS that need to be
co-routed

- 2 or more network media channels can be treated together (co-routed).
IETF GMPLS control plane has already a set of mechanisms to consider this.

Regarding the document itself, most of the editor's notes have been
removed. The content has been re-arranged for clarity. Also, some sections
have been merged to avoid redundancies.

Please consider reviewing the document and providing inputs. We are
looking forward to receiving comments :-)

Best Regards,

   Oscar

El 05/06/13 18:53, "[email-masked]" <[email-masked]>
escribió:

>
>A new version of I-D, draft-ogrcetal-ccamp-flexi-grid-fwk-03.txt
>has been successfully submitted by Oscar Gonzalez de Dios and posted to
>the
>IETF repository.
>
>Filename:       draft-ogrcetal-ccamp-flexi-grid-fwk
>Revision:       03
>Title:          Framework and Requirements for GMPLS based control of Flexi-grid
>DWDM networks
>Creation date:  2013-06-05
>Group:          Individual Submission
>Number of pages: 30
>URL:
>http://www.ietf.org/internet-drafts/draft-ogrcetal-ccamp-flexi-grid-fwk-03
>.txt
>Status:
>http://datatracker.ietf.org/doc/draft-ogrcetal-ccamp-flexi-grid-fwk
>Htmlized:
>http://tools.ietf.org/html/draft-ogrcetal-ccamp-flexi-grid-fwk-03
>Diff:
>http://www.ietf.org/rfcdiff?url2=draft-ogrcetal-ccamp-flexi-grid-fwk-03
>
>Abstract:
>   This document defines a framework and the associated control plane
>   requirements for the GMPLS based control of flexi-grid DWDM networks.
>   To allow efficient allocation of optical spectral bandwidth for high
>   bit-rate systems, the International Telecommunication Union
>   Telecommunication Standardization Sector (ITU-T) has extended the
>   recommendations [G.694.1] and [G.872] to include the concept of
>   flexible grid.  A new DWDM grid has been developed within the ITU-T
>   Study Group 15 by defining a set of nominal central frequencies,
>   channel spacings and the concept of "frequency slot".  In such
>   environment, a data plane connection is switched based on allocated,
>   variable-sized frequency ranges within the optical spectrum.
>
>
>
>
>
>The IETF Secretariat

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