Question about propagation and queuing delays

Robert E.Seastrom rs at seastrom.com
Mon Aug 22 19:29:37 UTC 2005



"Howard, W. Lee" <Lee.Howard at stanleyassociates.com> writes:

> Do carrier ISPs classify their voice traffic as Really 
> Important, and everybody else's data as Best Effort?  This 
> isn't just selfishness, since We All Know voice is less
> tolerant of latency and jitter than TCP.

We do?

Try to keep a single-TCP-stream session over 500 mbit/sec of goodput
halfway across the country sometime.  Most of us who have VoIP boxes
have 20ms or better jitter playout buffers.  Ever (successfully) talk
to someone over a GSM handset when their coverage was a little
marginal?  The human ear is a marvelous tool compared to a TCP timer.

Apologies if "We All Know" was supposed to be a cue to sarcasm or irony...

                                        ---Rob





More information about the NANOG mailing list