Subject: RE: [PCN] PCN updated charter

From: "Anna Charny \(acharny\)" <[email-masked]>
Date: Wed, 29 Nov 2006 17:28:39 -0500

Hi Lars,

More below... 

>> I interpret he above to mean that you propose to work on the encoding

>> and the actual marking decisions at the internal PCN router (as well 
>> as one deployment model and prob statement), but that the edge 
>> behavior should come later (after re-chartering).  Is that a correct 
>> interpretation?

>Right.

>> I worry about taking the consideration of edge behaviors out of the 
>> charter.
>> The primary cause of this worry is that  edge behaviors depend on the

>> meaning of  the marking. For example, if the marking is "red- like" 
>> (e.g.
>> virtual-queue based) its meaning is quite different than if the 
>> marking is excess-rate based (e.g. token-bucket based", and the 
>> appropriate edge behavior, to do "the right thing",  needs to reflect

>> the meaning of the marking.  I just cannot see how you can completely

>>divorce one from the other meaningfully.

>I agree that the meaning of the markings is important for the edge
algorithm and that 
>the two are difficult to separate.

>But that wasn't my point. Without even going into the semantics of
various markings, a 
>number of issues have been brought up with regards to _encoding_ this
information using 
>the ECN bits, DSCPs, IP options, etc. This should be worked out first,
because the
>encoding choices may limit what marking semantics can be defined later,
which in turn
>affects what edge behaviors are possible.

So just to make sure we are on the same page:
I think the above means that 

A) you propose to first deal with the encoding 
B) you agree that marking semantics (and hence any standardization of
the marking *mechanisms* (e.g. when to mark)) must be looked at together
C) you propose to not deal with edge behaviours until recahrtering

If that is correct, then this implies that we will NOT discuss the
marking semantics/mechanisms (beyond encoding) before rechartering at
all. That would mean, I think the following

1) limit the current charter to: 
        * problem/arcitecture draft
        * encoding 
        * Intserv over DiffServ deployment model
        * include a rechartering milestone with specific work items (see
below)

2) move to after the *after-rechartering*
        *  marking behavior at the interior node
        *  edge behavior
        *  other deployment models
        *  other stuff currently listed in the proposed charter, which
includes:
            ->a generic analysis of the signaling extensions required to
support PCN.
            ->at least one example solution implementing the framework
and its performance evaluation (e.g. simulation results), to provide
evidence of the viability of the proposed standard in the proposed
deployment models
            -> an applicability statement 
            -> an analysis of the manageability issues of a PCN region
        * other stuff initially planned to be dealt with after
rechartering
          (e.g. other trust models,  multiple PCN domains, etc)

I guess this is possible in principle, but doesn't it seems to be a bit
light on the near-term deliverables before the rechartering, and overly
heavy on the after-rechartering phase?  
      
Anna 

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---

From: Lars Eggert <[email-masked]>
Date: Wed, 29 Nov 2006 16:27:28 -0800

>         * include a rechartering milestone with specific work items  

Exactly.

>           (e.g. other trust models,  multiple PCN domains, etc)

I'd probably like to move some of this into a third charter phase,  
such as the "other deployment models" and maybe some of the "other  
stuff". But at least the marking behavior and edge behavior should  
come after the first recharter.

> heavy on the after-rechartering phase?

It is. We're trying to charter new work with more restrictive initial  
scopes and have more frequent recharter points than WGs with "old"  
charters. The idea is that this will focus the energy of the group on  
fewer current work items and hopefully aid overall progress. Minor  
recharters such as the ones I proposed for PCN tend to go through the  
IESG relatively quickly these days.

Lars