Stephen Stuart stuart at
Sat Nov 16 04:56:53 UTC 2002

> - Coast-to-coast "guaranteed latency" seems too low in most cases that =
> I've seen. Not calling CEOs and marketers liars but the real world doesn't =
> seem to do as well as the promises. As VOIP takes off "local" IP exchanges =
> will continue/increase in importance because people won't tolerate high =
> latency.  What percentage of your phone calls are local?

Those guarantees typically have nothing to do with actual service
delivery. The test is what exception conditions are identified in the
service level agreement, and the details of how the latency number is
measured. Is it a direct measurement that can be independently and
instantaneously verified, or is it a POP-POP number that uses
techniques like averaging over a month or omitting the customer edge
portion of the infrastructure in order to engineer a number that (a)
looks impressive and (b) will never be violated even in the face of
major outages.

Which is worse - the marketeers that invent performance fiction like
that, or the customers who go chasing after a lower number without any
analysis of how that number is determined?


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