Subject: Re: [Roll] draft-ietf-roll-protocols-survey-00

From: Philip Levis <[email-masked]>
Date: Tue, 2 Sep 2008 13:47:33 -0700

On Aug 27, 2008, at 7:45 AM, Drake, John E wrote:

> JP,
>
> I thought that was exactly Adrian's point.
>
> If you evaluate a bunch of routing protocols as they exist today in a
> new operational environment and conclude that none of them are
> appropriate, then you have no choice but to conclude that you need to
> invent at least one, but probably many, new routing protocols.  It's  
> not
> like this hasn't been done before.
>
> I took Adrian's note to say that doing this is not sufficient and that
> what needed to be done was to characterize the new operational
> environment, propose changes needed in each routing protocol to  
> address
> the new operational environment, and then evaluate these changes.

Sorry for taking so long to reply; I spent the past week off the grid  
and so was not in email contact.

This seems to be an argument about the scope of the document.  
Currently, the draft simply examines *existing* protocols to determine  
if any of them meet the requirements of ROLL. If the answer to this  
question is "yes," then ROLL does not need to consider how to come up  
with a protocol that meets its needs. If the answer to this question  
is "no," then ROLL needs to discuss how best to proceed. Doing so  
could be either extending existing protocols or defining new ones; the  
draft takes no position on this.

In other words, proposing changes to existing protocols should be in a  
subsequent draft, not this one. We first need to agree -- in writing  
-- whether any proposals of any kind are needed at all. Should I read  
this discussion as consensus on the conclusion so far?

Phil
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---

From: JP Vasseur <[email-masked]>
Date: Wed, 03 Sep 2008 06:43:37 +0200

Hi Phil,

> this discussion as consensus on the conclusion so far?

Not yet ;-) This is why we'll have an interim meeting (for a face to face
meeting) + Discussion on the mailing list, at which point we should draw a
consensus to move forward. We have to remember that non-IP solution continue
to make progress and we do now to move fast considering the demand for
IP-based solutions. Routing is of course a key component of the overall
architecture. So I would like to be able to converge (should all the
requirements document be last called soon) on whether we can find a routing
protocol that meet the requirement *and* whether we can extend an existing
routing protocol to meet these requirements without having to "twist" its
design. If the answer is no, we'll need to re-charter and quickly work on a
solution.

Could you look at Adrian's comment on the document ? I'll do a WG chair
review this week, it would be nice to have a new revision before the interim
meeting.

Thanks.

JP.

---

From: "Adrian Farrel" <[email-masked]>
Date: Thu, 4 Sep 2008 10:36:27 +0100

Hi Phil,

[SNIP]

> Currently, the draft simply examines *existing* protocols to determine  if 
> any of them meet the requirements of ROLL. If the answer to this  question 
> is "yes," then ROLL does not need to consider how to come up  with a 
> protocol that meets its needs. If the answer to this question  is "no," 
> then ROLL needs to discuss how best to proceed. Doing so  could be either 
> extending existing protocols or defining new ones; the  draft takes no 
> position on this.

I think that is fine, but I read the infamous table in your I-D as saying 
that some (many? most?) of the protocols could not be extended (i.e. "fail" 
rather than "?"). The problem with the whole thing is that it is almost 
always possible to bodge a protocol to do anything you want :-)

Maybe it would be better to analyse into five categories:
- base protocol does what we want
- base protocol with existing extensions does what we want
- base protocol could be extended with minor extensions to do what we want
- base protocol would need major extensions to do what we want
- protocol cannot be made to do what we want

> subsequent draft, not this one. We first need to agree -- in writing  --  
> whether any proposals of any kind are needed at all. Should I read  this 
> discussion as consensus on the conclusion so far?

Cheers,
Adrian