North American Network Operators Group

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Re: T1 Circuit actual throughput 1290Kbps

  • From: Mark Milhollan
  • Date: Fri Jul 10 11:09:26 1998

"Patrick W. Gilmore" writes:
>That is.... well, not correct.  

It certainly has incorrect elements, but their response is correct in
general -- there exists overhead, in some cases substantial overhead.

>PPP overhead is not even close to 200 Kbps on a T1.  

Without information on the traffic being handled this statement cannot
be supported.  I agree that its doubtful.

>I believe MRTG includes the overhead in it's graphs. 

MRTG has no "smarts" in this regard.  Whether or not overhead is
included is determined by the agent.  The agent is responding
according to a standard, private or public, which should, and usually
does, specify whether overhead is to be included.  Since the MIB being
discussed isn't known, to me, neither is the inclusion, or lack of,
overhead known.

>there are no "cells" in PPP. 

Its certainly possible that cells are being used, but their use should
not impact the delivered capacity.

>According to my MRTG graphs, the most I've ever gotten on a PPP
>encapsulated link is 1521.4 kb/s. 

Thats the sort of number we see as well on a general traffic mix.