T3 Latency

Sat Feb 17 07:37:48 UTC 2001

Chuck,

The question posed by Chris, "how long is your access line"?, is a rather 
important data point before answering your question.  I have a T3 that is
about 15 miles long.  It runs between two 7500 routers.  Its minimum ping
round trip time with 100 byte pings is 2 ms.  It is not very heavily loaded
with peaks of about 10 Mb/s today and the max round trip time was 21 ms.

So that should give you some minimal bounds of what you might expect.  As
the saying goes your mileage may vary.  Speed of light does play in here,
if the circuit is longer.  Also intervening electronics such as a frame cloud
or telco muxes also add latency.

Walt