Re: [CCAMP] Still have issues in WSON Processing HOP Attribute Encoding in draft-ietf-ccamp-wson-signaling-08

[Leeyoung <[e-mail]>]

Hi Lou,

Good point on RBI info! I can think of the RB Identifier (32 bit field) to imply the node/interface to which wavelength conversion would take place if we were to use LSP_REQUIRED_ATRIBUTES object. In other words, making the RB Identifier globally significant in a domain, per hop treatment of the RBs is possible. 

On the other hand, a better way to treat Resource Block Information seems to be using an alternative way (i.e., using HOP Attributes/ERO subobject per [RSVP-RO]). 

If making the RB ID globally significant creates a problem, we need to make some technical changes to the draft. Let me know what you think.

Regards,
Young 

-----Original Message-----
From: Lou Berger [mailto:[e-mail]] 
Sent: Monday, August 04, 2014 5:30 PM
To: Leeyoung
Cc: CCAMP; [e-mail]
Subject: Re: [CCAMP] Still have issues in WSON Processing HOP Attribute Encoding in draft-ietf-ccamp-wson-signaling-08

Young,
    Thanks for the quick response.  I "get" how WA method works, but am less clear how Resource Block Information (e.g., Regeneration control and  Attribute Conversion control) works per node. For example, how would control of wavelength conversion at a particular node work?

Perhaps just running through this one simple case will help...

Again, as a reminder, the desire is to document existing intent rather than redefining the solution.

Much thanks,
Lou

On 8/4/2014 5:08 PM, Leeyoung wrote:
> Hi Lou,
>
> Since the LSP_REQUIRED_ATTRIBUTES object is meant to allow each 
> transit node to inspect the TLV's under it, each transit node will 
> inspect RBI or WA method and apply if it has relevance for the node; 
> otherwise just pass to the next hop. (Section 5 of RFC 5420 has this 
> clause: "This means that this object SHOULD only be used for 
> attributes that require support at some transit LSRs and so require 
> examination at all transit LSRs.")
>
> This may not be optimal but a way to get around technical changes as you pointed out not to do so at this moment. 
>
> If we want this to be optimal and require technical changes to the draft, we can go with an alternative, utilizing [RSVP-RO] draft with ERO subobject/HOP Attributes to encode RBI or WA method as its TLVs. 
>
> Whichever the WG wants, we can go either way. 
>
> Thanks,
> Young
>
> -----Original Message-----
> From: Lou Berger [mailto:[e-mail]]
> Sent: Monday, August 04, 2014 3:44 PM
> To: Leeyoung; CCAMP; [e-mail]
> Subject: Re: [CCAMP] Still have issues in WSON Processing HOP 
> Attribute Encoding in draft-ietf-ccamp-wson-signaling-08
>
> Young,
>    
> On 8/4/2014 4:29 PM, Leeyoung wrote:
>> Hi,
>>
>> Lou, here's my comment on your comment. In a nutshell replacing [RSVP-RO] with [RFC5420] will solve the confusion. 
>>
>> Please see in-line for details.
>>
>> Thanks,
>>
>> Young
> So you are saying that Resource Block Information and Wavelength Assignment Method are encoded end-to-end and *never* have hop/node/interface specific meaning (as they are each encoded as an Attribute TLV in an LSP_REQUIRED_ATTRIBUTE object), is this correct?
>
> ARE YOU SURE?  
>
> How do you envision the LSP_REQUIRED_ATTRIBUTE object conveying 
> per-hop information? (As discussed in section 3.2 and the first 
> paragraph on section 4.2.)
>
> Lou
> ....
>
>
>