Re: [Gen-art] [CCAMP] Gen-art LC review: draft-ietf-ccamp-flexigrid-lambda-label-04

Ciao Daniele.

SP's hat on, I need to disagree with you there.

What Adrian proposes allows me to add new pieces of equipment to address 
traffic needs, without waiting for an NMS release supporting 100% of the 
feature I use. In this situation, I can choose between upgrading or 
waiting for the full package alignment: it remains my call, on a case by 
case basis. The wording also emphasizes the generalized beauty of GMPLS: 
new label encodings should not prevent the management of other protocol 
aspects ("be liberal in what you accept...).

What you suggest would prohibit that scenario, i.e., I need wait for 
fully-featured NMS, whatever the network is capable of. This is 
sometimes not acceptable: service needs prevail on fully detailed 
management, the NMS should not be a network limitation. The current 
example, where label resolution could rely on a (temporary?) external 
tool, makes it even more realistic.

Regards,

Julien

Sep. 09, 2015 - daniele.ceccarelli@ericsson.com:
> Hi Adrian,
>
> I tend disagree with this statement:
>
> "My contention is that it is quite likely that someone would try to use a legacy NMS to manage a new flexigrid network since "it is all just GMPLS". And it is not an unreasonable assumption to be able to do this if some fields (for example, label) can be displayed as opaque quantities."
>
> I'm not sure an operator would be happy to see 96 channels called lambda1, lambda2,..., lambda 96 from his NMS while the network is flexi grid.
> We'll have to face these issues when we'll be speaking about YANG models for flexi grid but for the time being let's be on the safe side and address the compatibility issue as you're suggesting.
>
> Cheers,
> Daniele
>
>> -----Original Message-----
>> From: Adrian Farrel [mailto:adrian@olddog.co.uk]
>> Sent: martedì 8 settembre 2015 18:02
>>
>> Hi Daniele,
>>
>>> Thanks for the careful review and your comments.
>>> I pretty much agree with Adrian's reply but I think explicitly having
>>> some backward compatibility text in the draft could be helpful.
>>>
>>> Adrian, authors, I'd suggest changing section 5 from "Manageability
>>> Considerations" to "Backward Compatibility and Manageability
>> Considerations"
>>> adding to the existing text backward compatibility considerations
>>> against legacy GMPLS and legacy NMS (mostly what you've already written
>> below).
>>
>> I can work on this.
>>
>>> WRT the legacy NMS I don't think it is a reasonable scenario, since
>>> before operating the nodes with a GMPLS implementing this draft, the
>>> node needs to be configured and the NMS must be flexi-grid compatible.
>>
>> But wait! This is exactly the point.
>> Suppose there is an NMS that is inspecting an LSP at a transit node.
>> That NMS does not need to be flexigrid compatible to read the details of the
>> LSP at that transit node.
>> However, it *does* need to have some capabilities in order to not barf when
>> it gets the response from the LSR.
>> The first thing is to handle a 64 bit label as an opaque string.
>> The advanced thing is to be able to parse out the 64 bits into the relevant
>> fields.
>>
>> Indeed, to request the setup of a flexigrid LSP does not require a flexigrid
>> compatible NMS since it is possible to simply request a path and bandwidth
>> (or not even request a path).
>>
>> My contention is that it is quite likely that someone would try to use a legacy
>> NMS to manage a new flexigrid network since "it is all just GMPLS". And it is
>> not an unreasonable assumption to be able to do this if some fields (for
>> example, label) can be displayed as opaque quantities.
>>
>> Now, if you are talking about an EMS, I completely agree.
>>
>> Cheers,
>> Adrian
>>
>
> _______________________________________________
> CCAMP mailing list
> CCAMP@ietf.org
> https://www.ietf.org/mailman/listinfo/ccamp
>

_________________________________________________________________________________________________________________________

Ce message et ses pieces jointes peuvent contenir des informations confidentielles ou privilegiees et ne doivent donc
pas etre diffuses, exploites ou copies sans autorisation. Si vous avez recu ce message par erreur, veuillez le signaler
a l'expediteur et le detruire ainsi que les pieces jointes. Les messages electroniques etant susceptibles d'alteration,
Orange decline toute responsabilite si ce message a ete altere, deforme ou falsifie. Merci.

This message and its attachments may contain confidential or privileged information that may be protected by law;
they should not be distributed, used or copied without authorisation.
If you have received this email in error, please notify the sender and delete this message and its attachments.
As emails may be altered, Orange is not liable for messages that have been modified, changed or falsified.
Thank you.