Re: [CCAMP] WG Last Call on draft-ietf-ccamp-lsp-diversity-03

["Zafar Ali (zali)" <[e-mail]>]

Hi John:

Please see in line.

Thanks

Regards … Zafar

From: "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>
Date: Friday, February 7, 2014 12:12 PM
To: zali <[e-mail]<mailto:[e-mail]>>, Fatai Zhang <[e-mail]<mailto:[e-mail]>>, "BRUNGARD, DEBORAH A" <[e-mail]<mailto:[e-mail]>>, "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>
Subject: RE: [CCAMP] WG Last Call on draft-ietf-ccamp-lsp-diversity-03

Zafar,

I don’t feel like rehashing all of this, but as was pointed out to you repeatedly, the reason the key is called a ‘path key’ is that it refers to a path and a path can be used by more than one LSP.  This means that the persistence of a path and its associated path key is not tied to the persistence of an individual LSP.


One of the attributes of the Path is its ingress and egress end-point addresses. Within a given end-points, only few routes can be used for multiple LSPs. Specifically, if path key: LSP relationship is 1:n, we are dealing with a really low value of n in a typical network. The fact remains given that Path key is 16 bit, draft-zhang-ccamp-route-exclusion-pathkey-00  has serious scaling limitations.

More importantly, the discussion of the path key draft is beside the point.  It is your draft that is under discussion and it is your draft with which I have problems.


I did not brought draft-zhang-ccamp-route-exclusion-pathkey-00 into this email thread, it was brought in by you.

Yours Irrespectively,

John

From: Zafar Ali (zali) [mailto:[e-mail]]
Sent: Friday, February 07, 2014 8:47 AM
To: John E Drake; Fatai Zhang; BRUNGARD, DEBORAH A; [e-mail]<mailto:[e-mail]>
Subject: Re: [CCAMP] WG Last Call on draft-ietf-ccamp-lsp-diversity-03

Hi John-

Only if you deploy a 100-s of PCE (PCE node ID-es) so scaling really becomes a function of number of PCE in the network (this does not fly). Also fact remains the  draft-zhang-ccamp-route-exclusion-pathkey-00<http://tools.ietf.org/html/draft-zhang-ccamp-route-exclusion-pathkey-00> requires a PCE that needs to keep state of ALL LSPs it has served (as long as they exists in the network). Most of the recent requirements are to deploy a single PCE, which mean the NETWORK can only serve 64K LSPs (PCE Path key is 16 bit), which also does not fly, either.

Thanks

Regards … Zafar

From: "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>
Date: Friday, February 7, 2014 10:51 AM
To: zali <[e-mail]<mailto:[e-mail]>>, Fatai Zhang <[e-mail]<mailto:[e-mail]>>, "BRUNGARD, DEBORAH A" <[e-mail]<mailto:[e-mail]>>, "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>
Subject: RE: [CCAMP] WG Last Call on draft-ietf-ccamp-lsp-diversity-03

Zafar,

The conclusion of the long discussion was that your claims, repeated in your email below, regarding the path key draft were simply incorrect.

Yours Irrespectively,

John

From: CCAMP [mailto:[e-mail]] On Behalf Of Zafar Ali (zali)
Sent: Friday, February 07, 2014 7:05 AM
To: Fatai Zhang; BRUNGARD, DEBORAH A; [e-mail]<mailto:[e-mail]>
Subject: Re: [CCAMP] WG Last Call on draft-ietf-ccamp-lsp-diversity-03

Hi Fatai, John-

We had a long discussion and agreement that draft-zhang-ccamp-route-exclusion-pathkey-00<http://tools.ietf.org/html/draft-zhang-ccamp-route-exclusion-pathkey-00> requires a PCE that needs to keep state of ALL LSPs it has served (as long as they exists in the network). There is also a scaling issue as it limits number of LSPs PCE can serve. So calling it is "simple" is NOT a correct statement. You solution requires a path-stateful PCE.

Also to note from last IETF meeting minutes: http://www.ietf.org/proceedings/88/minutes/minutes-88-ccamp
Lou Berger: "PCE: operating without the PCE is still in the scope of this WG." Our solution is without the use of PCE (signaling based).

Thanks

Regards … Zafar

From: Fatai Zhang <[e-mail]<mailto:[e-mail]>>
Date: Friday, February 7, 2014 1:50 AM
To: "BRUNGARD, DEBORAH A" <[e-mail]<mailto:[e-mail]>>, "[e-mail]<mailto:[e-mail]>" <[e-mail]<mailto:[e-mail]>>
Subject: Re: [CCAMP] WG Last Call on draft-ietf-ccamp-lsp-diversity-03

Hi Deborah and all，

I think you might have noticed that there is another draft (http://tools.ietf.org/html/draft-zhang-ccamp-route-exclusion-pathkey-00), which describe a simple solution to address the same requirement as draft-ietf-ccamp-lsp-diversity and there were lots of discussion on the both drafts in the WG list.

In my understanding from the WG discussion, I think many people prefer draft-zhang because it is more straightforward and simple.

The authors of draft-zhang tried to contact the authors of draft-ietf-ccamp-lsp-diversity to discuss how to move forward these drafts, but nothing happened.

Therefore, the guidance from the WG chairs on how to move forward the both drafts (e.g, pick up one of them to go or any other suggestions) would be appreciated.




Best Regards

Fatai

From: CCAMP [mailto:[e-mail]] On Behalf Of BRUNGARD, DEBORAH A
Sent: Friday, February 07, 2014 4:06 AM
To: [e-mail]<mailto:[e-mail]>
Subject: [CCAMP] WG Last Call on draft-ietf-ccamp-lsp-diversity-03

All,

This starts a two-week working group last call on draft-ietf-ccamp-lsp-diversity-03.

This working group last call ends Feb. 20th. Please send your comments to the CCAMP mailing list.

Deborah and Lou