Re: [CCAMP] Vendor-Specific Application Code in draft-ietf-ccamp-rwa-wson-encode

[Leeyoung <[e-mail]>]

Hi Adrian,

I think you misinterpreted what was said. 

>> Now, what is the purpose of standard FECs and modulations in the AI? Given
>> several choices each vendor may support in its device, the path computation
>> would find a matched types for FEC and modulation for a given optical path. 
>> This is what is intended when optical signal processing constraints were 
>> proposed as part of path computation constraints in optical networks. 

> The case you are making here is for no standard control plane!
> What is the point of standardising if there is never any interworking?
> But actually, we know about interworking at the physical layer, and (more important) we know about a single, > end-to-end control plane that spans multiple vendor devices. It all exists.

The standard AI allows to match optical processing constraints (including FECs and Modulations implied in an AI). This information is advertised that a PCE would be able to compute an optical path matching AIs for all the devices to dertermine a feasible path. I am talking about this standard control plane work. This is what was intended in the draft. 

Regards,
Young

-----Original Message-----
From: Adrian Farrel [mailto:[e-mail]] 
Sent: Thursday, January 29, 2015 7:24 AM
To: Leeyoung; 'Varma, Eve L (Eve)'; [e-mail]; 'Lam, Hing-Kam (Kam)'; [e-mail]; [e-mail]
Cc: [e-mail]; [e-mail]; [e-mail]; [e-mail]
Subject: RE: [CCAMP] Vendor-Specific Application Code in draft-ietf-ccamp-rwa-wson-encode

Hi again,

> There is always a priori knowledge in optical network domain as to who 
> are you interfacing with. So you know which vendor you are interfacing. 
> If you do not know, then you are in trouble.

Hmmm. It is exactly type of trouble we are trying to detect and protect against.

I refute your statement of a priori knowledge. I think there is a priori intention, but not knowledge. Unless you have very good eyesight or someone at the other end of the fiber when you give it a tug, you don't know. And even then. Fibering errors happen from time to time. Consider, in particular a patch panel.

> Now, what is the purpose of standard FECs and modulations in the AI? Given
> several choices each vendor may support in its device, the path computation
> would find a matched types for FEC and modulation for a given optical path. 
> This is what is intended when optical signal processing constraints were 
> proposed as part of path computation constraints in optical networks. 


The case you are making here is for no standard control plane!
What is the point of standardising if there is never any interworking?
But actually, we know about interworking at the physical layer, and (more important) we know about a single, end-to-end control plane that spans multiple vendor devices. It all exists.

Of course, we can fall back into the old-style vendor islands, and many like to do so. But it is not a compulsory deployment model.

> There is very little chance for vendor specific FECs and Modulations will match
> even if they are identified with the OUI code. 

You have it the wrong way round!
The OUI is largely to protect against expectations of interworking when none can exist.
It might (much less frequently) be used to describe the way that vendorA and vendorB pick FECs and modulations in order to achieve interworking.

Adrian