Re: [CCAMP] New Liaison Statement, "LS86 - Comments on WSON Impairment Work in CCAMP"

[Greg Bernstein <gregb at grotto-networking.com>]

Hi folks, I just reviewed this liaison (LS-86) and had a few questions 
and thoughts (from a individual perspective not IETF, CCAMP...).
In section 3.1.1 of the WSON Impairments Framework draft we categorize 
the different types of impairment aware RWA computations. This section 
does not address "black links".

In section 3.1.2 we discuss impairment information sharing constraints. 
This section includes the information sharing constraints of a "black 
link". From our understanding of the "black link" concept, no impairment 
parameters would be available for the control plane to share with 
computational entities for the subnetwork. We did not take this to mean 
that the owner of the "black link" would not know whether a path across 
that link was viable, or that all paths across the black link are viable.

From our understanding of "black links" it did not appear that every 
black link must be terminated by 3R regenerators as stated in the 
liaison: "“black link” is a viable pre engineered optical path between 
3R regenerators". We assumed that a black link could terminate on a 
receiver. Hence we took a more general view of a black link as an 
network element with unknown impairment properties whose impairment 
effects could be calculated by its owner (not the general control plane).

Best Regards

Greg B.

Greg Jones(ITU-T SG 15) wrote:
> Title: LS86 - Comments on WSON Impairment Work in CCAMP
> Submission Date: 2009-10-27
> URL of the IETF Web page: https://datatracker.ietf.org/public/liaison_detail.cgi?detail_id=603 
> Please reply by 2010-05-31
>
> From: Greg Jones(ITU-T SG 15) <tsbsg15 at itu.int>
> To: IETF ccamp Working Group(dbrungard at att.com,lberger at labn.net)
> Cc: paf at cisco.com
> adrian.farrel at huawei.com
> rcallon at juniper.net
> ccamp at ietf.org
> yoichi.maeda at ntt-at.co.jp
> sjtrowbridge at alcatel-lucent.com
> Reponse Contact: tsbsg15 at itu.int
> greg.jones at itu.int
> hiroshi.ota at itu.int
> Technical Contact: malcolm.betts at huawei.com
> Purpose: For comment 
> Body: 
> Attachment(s):
>      LS86 - Comments on WSON Impairment Work in CCAMP - pdf (https://datatracker.ietf.org/documents/LIAISON/file719.pdf)
>
>
>
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>   

--
===================================================
Dr Greg Bernstein, Grotto Networking (510) 573-2237