nanog mailing list archives

Re: T1 Circuit actual throughput 1290Kbps


From: Nathan Stratton <nathan () skipper robotics net>
Date: Thu, 9 Jul 1998 00:30:50 -0400 (EDT)

On Thu, 9 Jul 1998, Tony S. Hariman wrote:

Does anybody have experience having a T1 circuit with PPP 
encapsulation getting only 1290 Kbps maximum throughput looking 
at "sh int" result from cisco router or MRTG ?

Oh, around 1536 :-)
 
This is the explanation our upstream provider gave us:

You have a 1.536Mbps port.  However, there is the overhead from 
PPP and the translation overhead which takes place in all circuits.  
Judging by your settings that limit ends up somewhere between 
1.3 and 1.4.  This overhead would be the non-data portion of cells 
or frames for example. For example, you might have 1.3 Mbps of 
data which gets framing or cell information appended onto it before 
sending taking up additional bandwidth.  It is to be expected in all 
circuits.

Hehe, find a new ISP. There is some overhead with PPP, but it is not close
to that amount. Most likely your ISP does not have the bandwidth to
deliver all of your bandwidth. 
 
Thank you for your help.

No problem.
 
<>
Nathan Stratton                         Telecom & ISP Consulting
www.robotics.net                        nathan () robotics net

Tony S. Hariman
http://www.tsh.or.id
Tel: +62(21)574-2488
tonyha () compuserve com



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