Long haul latency calculation?

In message <200109301909.AA29032658@mail.turbonet.net>, "Christopher Wolff" wri

Dear Nanog:

I was wondering if there is a benchmark for long-haul circuit latency... For
example if I had a T1 circuit with 2900 miles between the two end-points (and
assuming the provider is best case scenario) can I do something like (miles*la
tencyfactor) = 5 ms for 2900 miles?

It's called "speed of light lag"... If I recall correctly,
the speed of light in fiber is about .65c, where c is the speed of
light in a vacuum (300,000 km/sec).

    --Steve Bellovin, http://www.research.att.com/~smb