Re: [RRG] yetAnotherProposal: AS-number forwarding

[Lixia Zhang <lixia@CS.UCLA.EDU>]

On Mar 10, 2008, at 5:34 AM, Xu Xiaohu wrote:

> > -----邮件原件-----
> > 发件人: owner-rrg@psg.com [mailto:owner-rrg@psg.com] 代表 Lixia Zhang
> > 发送时间: 2008年3月10日 12:22
> > 收件人: Lars Westberg
> > 抄送: rrg@psg.com
> > 主题: Re: [RRG] yetAnotherProposal: AS-number forwarding
> >
> >
> > On Mar 9, 2008, at 11:40 PM, Lars Westberg wrote:
> >
> > > Hi,
> > > I haven't had time to make a draft but I think it make sense for the
> > > discussion. However, I don't know if it already have been discussed
> > > so....
> > >
> > > The proposal are simple: re-use AS-numbers into the forwarding of
> > > packets such that prefixes could be aggregated per AS. One simple
> > > implemetation is that the packets are tunneled and that the tunnel-
> > > address is associated to a AS-number. The AS-numbers can be assigned
> > > to the IP-addresses by DNS or by define a small address-prefix to  
> > > AS-
> > > numbers.
> > >
> > > Comments?
> > in an ideal world, yes having AS number as part of address used for
> > routing has great benefit.  see the slide from a talk in 2006
> > (http://www.cs.ucla.edu/~lixia/0612Australia.pdf
> > , but ignoring the title), slide 17 & 18 is about this.
> > If we had a chance to influence address structure, you'd want to
> > include other info in addition to AS (as large ASes span large areas,
> > TE would want more info to do better job).
> > we have another paper (http://www.cs.ucla.edu/~rveloso/papers/
> > giro.pdf) showing the benefit for including location info (which
> > should be a subfield after AS number)
>
> With support of routing aggregation at any desired level, I can't  
> image that
> GIRO alone can do much help in routing scalability issue unless it  
> brings in
> some id/locator split idea, like GSE, SIX/ONE or HRA.

- as you can see from the talk slides, yes the basic idea IS to
  separate edge prefixes from transit routing space

- to the specific question of whether aggregation alone
  (by AS and then location) can help much with routing scalability:
  (a) it can indeed help a lot based on the analysis using today's
      routing table content
  (b) but if we want the global routing system to scale *independently*
      from the edge user site growth, then the separation becomes
      necessary.

The reason I referred to the 2nd paper is merely to show the benefit  
of including location info in address; not sure where you got the  
implication of no-split.

Lixia
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