Subject: Re: [RRG]

From: Michael Meisel <[email-masked]>
Date: Wed, 09 Apr 2008 22:54:40 -0700

Tony Li wrote:
> Hi all,
> 
> I'd like to turn now to the issue of the dynamics of the mapping function.
> In particular, how fast can we allow the mapping entries to be updated?  Do
> we need to constrain the overall flux of the mapping?
> 
> As always, a clear, succinct articulation of the correct questions is more
> valuable than a position statement.  ;-)

Hi Tony and all,

Sorry for my late response, Dan and I are both behind with our mailing 
list reading and just catching up this week.

I think we should ask this question in terms of the problems we are 
trying to solve. As we all know, one of these problems is the frequency 
of BGP updates today, which are largely coming from edge network. To put 
it a different way, the problem is that the reachability information for 
even the smallest of edge networks is announced globally. Each update 
requires a significant amount of processing by each node that it passes 
through. So the mapping system better not suffer from this same problem, 
or we haven't done any good!

So, specifically, we should be asking:

(1) Is the mapping function successful in preventing edge network 
reachability from being propagated into the global routing system?

(2) If yes, does it do so without simply moving the problem to the 
global mapping system?

Note that proposals that both (a) put reachability information into the 
mapping system and (b) involve any sort of push model start to look a 
lot like BGP, and therefore are going to have a hard time answering 
"yes" to (2) convincingly.

-Michael

--
to unsubscribe send a message to [email-masked] with the
word 'unsubscribe' in a single line as the message text body.
archive: <http://psg.com/lists/rrg/> & ftp://psg.com/pub/lists/rrg