T1 Circuit actual throughput 1290Kbps

Tony S. Hariman tonyh at noc.cbn.net.id
Thu Jul 9 03:44:26 UTC 1998

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 ?

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 

Thank you for your help.

Tony S. Hariman
Tel: +62(21)574-2488
tonyha at compuserve.com

More information about the NANOG mailing list