"Well-engineered" is a loaded term, and presumes unchanging routes are always the best way to engineer a network. With ATM, MPLS and other provider games the IP-level path may have very little to do with where your packets go.

perhaps my question was somewhat misleading... i was not implying that unchanging routes are good or bad. i was trying to understand with what confidence i can determine the IP route between two PoPs at any given instant. _well-engineered_ was meant to imply the isp has control over their network, and make controlled changes if required. thanks for the pointer. rajesh.

What you are looking for is the work done at MERIT and later the Skitter project at CAIDA. See www.caida.org for more infomation.

On Mon, 10 July 2000, Rajesh Talpade wrote:

...

At the risk of making a possibly naive request, could someone point me to data on ISP network performance (routing stability, packet loss, latency) ? I am primarily interested in the first metric, and am trying to understand the relative stability of large, _well-engineered_ ISP networks. In other words, with what degree of confidence can I predict the IP-level path between two PoPs of a large ISP. Please note that I am not getting into the general Internet performance here.

Somehow I get this feeling that the answer would be a fairly large...it depends ! It would be useful to understand the influencing factors as well.

-- Rajesh R. Talpade rrt@research.telcordia.com 973 829-4261 Telcordia Technologies