[nsp] Calculating ATM Cell transfer rates

[sthaug at nethelp.no]

> surely this would give you an inaccurate Cell rate - if
> we wanted to shape a PVC for 256Kbps - using Ciscos
> interpretation this would give you a cell rate of 603 cps
> based on 53 byte cells.  But 603 cps is only 231Kbps of
> actual payload data based on 48 bytes of payload per cell.
> Or am I mis-understanding the whole calculation process?

I am saying that the Cisco specification in kbps is based on 53 byte
cells. Thus if you want 256 kbps of *payload*, you have to specify
256*53/48 = 282 (or 283 if you round up) kbps in your Cisco router
config.

As I mentioned, you can check this yourself by using suitable debug
commands.

Steinar Haug, Nethelp consulting, sthaug at nethelp.no