Transit Analysis

Fri Feb 15 17:33:39 UTC 2002


> I'm trying to understand what techniques/solutions are available to
> determine which AS's would make good peering partners. If we look at our
> Transit stream to our upstream provider, I had heard the following from
> someone and would like to get some other opinions:
> 
> When trying to identify good AS candidates for peering from your transit
> traffic stream. It would seem that distinguishing the ingress traffic by
> not only the next-hop AS but also by the next-next-hop AS (or by the
> complete AS path) so that you can identify which customer or peer of your
> transit provider might be a likely interesting new peer for you. However,
> due to the concept of BGP traffic in the internet being asymmetrically
> distributed. It is not possible to exactly determine the real AS path of
> incoming traffic. The only reliable information is about the next-hop and
> the origin AS. Assuming that traffic is mostly symmetrical it is possible
> to "estimate" the distribution of ingress traffic on AS paths. While this
> assumption is questionable it at least allows to find out one (or some) of
> the several "potential" intermediate" ASNs for a given origin ASNs.
> 
> Is the above statement OK, and what about egress analysis, would that not
> also provide useful as that information is more reliable?  
>   
> -guy
> 
>