T1 Circuit actual throughput 1290Kbps

Thu Jul 9 04:30:50 UTC 1998

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 at robotics.net

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