Subject: [Pce] Opinion on adopting draft-ash-pce-architecture-01 as a PCE WG document ?

From: JP Vasseur <[email-masked]>
Date: Tue, 8 Mar 2005 11:36:52 -0600

All,

We discussed yesterday draft-ash-pce-architecure-01 
(http://www.ietf.org/internet-drafts/draft-ash-pce-architecture-01.txt) 
for which there was a pretty large consensus in the room to adopt it as 
a WG document.

Let us know bring this question on the list.

Could you please express your opinion on whether this draft should be 
adopted as a working group document (Y/N) ?

ps: note that comments were made yesterday (include a paragraph on 
unsolicited PCE path computation, ...) which should be taken care of in 
the next revision.

Thanks.

JP and Adrian.

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From: dimitri papadimitriou <[email-masked]>
Date: Tue, 08 Mar 2005 20:30:06 +0100

hi jp -

from my record the "statefull PCE" comment is also to be addressed as 
cases for which this would be useful is not described in the document

it may be actually be interesting to list all the comments that would 
require further work

thanks,
- dimitri.

JP Vasseur wrote:
> .

---

From: "Adrian Farrel" <[email-masked]>
Date: Tue, 8 Mar 2005 19:49:11 -0000

Hi Dimitri,

> cases for which this would be useful is not described in the document

I beg to differ.
Section 6.8 contains...

   Note that although this allows for optimal path
   computation and increased path computation success

...which is an implicit use case.

But also section 6.8 contains...
   There is benefit in knowing which LSPs exist, and their routing, to
   support such applications as placing a high priority LSP in a crowded
   network such that it preempts as few other LSPs as possible.  Note that
   preempting based on the minimum number of links might not result in the
   smallest number of LSPs being disrupted.  Another application concerns
   the construction and maintenance of a Virtual Network Topology [MRN].
   It is also helpful to understand which other LSPs exist in the network
   in order to decide how to manage the forward adjacencies that exist or
   need to be set up. The cost-benefit of stateful PCE computation would
be
   helpful to determine if the benefit in path computation is sufficient
to
   offset the additional drain on the network computational resources.

...which gives several applications.

> it may be actually be interesting to list all the comments that would

Yes, I think that would be useful.
In fact, I hope the editor is doing this to track the work for the draft.

Do either of these comments lead you to an answer to JP's question?

Thanks,
Adrian

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From: "Dean Cheng \(dcheng\)" <[email-masked]>
Date: Tue, 8 Mar 2005 12:15:58 -0800

Yes
>
>Could you please express your opinion on whether this draft 
>should be adopted as a working group document (Y/N) ?Y

---

From: Kenji Kumaki <[email-masked]>
Date: Wed, 09 Mar 2005 05:29:42 +0900

Yes.

-- 
Kenji Kumaki <[email-masked]>

---

From: JP Vasseur <[email-masked]>
Date: Tue, 8 Mar 2005 14:36:54 -0600

Hi Dimitri,

> it may be actually be interesting to list all the comments that would  

adopting this document as a WG document does not mean that the work is  
over of course (see my ps:) ... the question was "Could you please  
express your opinion on whether this draft should be adopted as a  
working group document (Y/N) ?"

Thanks.

JP.

>> (http://www.ietf.org/internet-drafts/draft-ash-pce-architecture 
>> -01.txt) for which there was a pretty large consensus in the room to  
>> adopt it as a WG document.
>> unsolicited PCE path computation, ...) which should be taken care of  
>> in the next revision.
>> Thanks.
>> JP and Adrian.

---

From: Eiji Oki <[email-masked]>
Date: Wed, 09 Mar 2005 06:27:54 +0900

Yes.

---

From: Jaudelice Cavalcante de Oliveira <[email-masked]>
Date: Tue, 8 Mar 2005 16:50:24 -0500 (EST)

> adopted as a working group document (Y/N) ?

Yes, definitely.

---

From: dimitri papadimitriou <[email-masked]>
Date: Tue, 08 Mar 2005 23:08:35 +0100

hi adrian, i don't think the point has been well understood then, the 
question is not whether you can or not find an example where it could be 
used but whether it is appropriate as part of this "architecture" document

now, to be more accurate here it can be advisable to start discussing 
what a path computation state more precisely means (in particular make 
the distinction between a path state and path computation state since 
they are different beasts) - which information it maintains and how this 
maintenance is expected to occur e.g. incremental - otherwise 
determination of the feasibility of this approach sounds difficult as 
part of this document

hope this clarifies my concerns,
- dimitri.

Adrian Farrel wrote:
>>>for which there was a pretty large consensus in the room to adopt it
> 
> as
> 
>>>a WG document.
>>>
> in

---

From: "[email-masked]" <[email-masked]>
Date: Wed, 09 Mar 2005 07:08:41 +0900

Yes,

 >We discussed yesterday draft-ash-pce-architecure-01 
(http://www.ietf.org/internet-drafts/draft-ash-pce-architecture-01.txt) for 
which there was a pretty large consensus in the room to adopt it as a WG 
document.
 >ps: note that comments were made yesterday (include a paragraph on 
unsolicited PCE path computation, ...) which should be taken care of in the 
next revision.

---

From: "Adrian Farrel" <[email-masked]>
Date: Tue, 8 Mar 2005 22:22:48 -0000

Hi,

Yes (and thanks for the off-line discussions).

It seems that the co-chairs are a little confused about what is an
architecture I-D and what is a framework I-D.
We will get some advice form our ADs when we meet them tomorrow morning,
and come back to y'all.

With regard to defining "what is state?"; this is clearly important to the
definition of what is "stateful". There is clearly a very wide spectrum of
state information, and many of the differences in opinion about the
meta-question must be dependent on different opinions of what comprises
state and how much state we are talking about. Clearly more discussion and
debate is needed.

In the context of a framework I-D, it is probably sufficient to state a
desire for (or against) stateful PCE, and to give a few examples to set
expectations of the range of potential options. In the context of a
requirements draft, it is necessary to understand which scenarios are
being addressed and what state is required to be retained.

So where does an architecture I-D fit in?
I'm not sure.

Adrian

----- Original Message ----- 
From: "dimitri papadimitriou" <[email-masked]>
To: "Adrian Farrel" <[email-masked]>
Cc: <[email-masked]>; "JP Vasseur" <[email-masked]>;
<[email-masked]>
Sent: Tuesday, March 08, 2005 10:08 PM
Subject: Re: [Pce] Opinion on adopting draft-ash-pce-architecture-01 as
aPCE WG document ?

---

From: dimitri papadimitriou <[email-masked]>
Date: Sat, 12 Mar 2005 00:11:11 +0100

hi adrian, see in-line concerning the architecture i-d fit question:

> So where does an architecture I-D fit in?

taking an analogy with RFC 3945, it would in the present case be a 
document that puts together the protocol building blocks i.e the 
PCC/E<->PCE communication, the discovery, the transactions, etc.

such document usually builds up as the work progresses to give provide 
at the end the glue between the different elements

thanks,
- dimitri.

>>used but whether it is appropriate as part of this "architecture"
> 
> document
> 
>>>   support such applications as placing a high priority LSP in a
> 
> crowded
> 
>>>   network such that it preempts as few other LSPs as possible.  Note
> 
> that
> 
>>>   preempting based on the minimum number of links might not result in
> 
> the
> 
>>>   smallest number of LSPs being disrupted.  Another application
> 
> concerns
> 
>>>   the construction and maintenance of a Virtual Network Topology
> 
> [MRN].
> 
>>>   It is also helpful to understand which other LSPs exist in the
> 
> network
> 
>>>   in order to decide how to manage the forward adjacencies that exist
> 
> or
> 
>>>   need to be set up. The cost-benefit of stateful PCE computation
> 
> would
> 
>>>be
>>>   helpful to determine if the benefit in path computation is
> 
> sufficient
> 
>>>to
>>>In fact, I hope the editor is doing this to track the work for the
> 
> draft.
>