North American Network Operators Group
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Re: Long haul latency calculation?

  • From: David Charlap
  • Date: Mon Oct 01 16:55:44 2001 
Christopher Wolff wrote:
> 
> 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*latencyfactor) = 5 ms for
> 2900 miles?

Speed of light is apprxoximately 2.998e+8 m/s (or 299,800,000 m/s),
which is approximately 186,287 miles/sec.

2900 mi / 186,287 mi/s = 0.01557s = 15.57ms.  This is the absolute
minimum latency you can possibly get over that distance.  Switching
performance and congestion will make your actual latency somewhat
larger.

-- David