Giuseppe Larosa Thu, 02/04/2010 - 05:18

Hello Olakun,

the number of cells per second that can be sent depend from:

ATM access link speed ( ATM E1 or better ATM E3 or so on)

traffic characteristics of PVCs or SVCs defined on the link.

Actually, ATM sends always ATM cells at access link speed, this is needed by the system and idle ATM cells are sent instead of silence.

An ATM E1: equivalent to 30 B channels

1920 kbps => 4528 cells / second

if a PVC with CIR 500 Kbps is defined, up to 500 Kbps = 1179 cells/second of user traffic are sent and in total 4528 cells/sec

The difference is made of idle cells

Hope to help


olakunle06 Thu, 02/04/2010 - 06:39

please what is the rate on STM-1 LINK.

Thanks for anticipated response

rtuttle Thu, 02/04/2010 - 07:30


The STM-1 (Synchronous Transport Module) is the SDH ITU-T fiber optic network transmission standard. It has a bit rate of 155.52 Mbit/s



This Discussion