[e2e] topological locality of Internet communication?

Ping Pan pingpan at cs.columbia.edu
Thu Nov 4 14:54:30 PST 2004


A few years ago, from Oregon Universoty (NLANR) and Belnet (Europe), the
AS-hop mean value is about 4. The max can be 7-8. I suspect that number is
larger now, as we have more national IP backbones around the globe.

Given the carriers will use AS aggregation for stability reasons, the actual
recorded AS hops in BGP route announcement may be smaller than the actual
path.

- Ping

> -----Original Message-----
> From: end2end-interest-bounces at postel.org 
> [mailto:end2end-interest-bounces at postel.org] On Behalf Of Lars Eggert
> Sent: Thursday, November 04, 2004 1:21 PM
> To: end2end-interest at postel.org
> Subject: [e2e] topological locality of Internet communication?
> 
> 
> Hi,
> 
> since we were just talking about Internet statistics:
> 
> I'm looking to get a feel of how much topological locality Internet 
> communication exhibits, to calibrate some simulations we plan to run.
> 
> Is anyone aware of measurements of how many "AS hops" typical 
> connections cross in the Internet? Ideal would be a CDF of "AS hops 
> crossed" for connection percentages.
> 
> (I thought about looking at the TTLs of incoming TCP packets 
> at servers, 
> infering the OS based on TCP characteristics like nmap and 
> using this to 
> guess the default outbound TTL for that OS. But that yields 
> IP hops, not 
> AS hops.)
> 
> Thanks,
> Lars
> -- 
> Lars Eggert                                     NEC Network 
> Laboratories
> 



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