T1 Circuit actual throughput 1290Kbp

Fri Jul 10 20:17:39 UTC 1998

>(!)  The cell tax is about 10% -- the SAR expands user data from 48
>bytes to 53 bytes, plus an additional amount of overhead for internal
>fragmentation on the final cell (AAL-5), plus overhead for whatever
>encapsulation mode is being used.

The cell tax is actually about 20%, based on the traces of the backbone IP
traffic. Reason for this is the additional overhead imposed of partially filled cells.

Fixwest 960926:

total packets seen = 15315121, total payload bytes seen = 4276560002
ATM framing bytes = 5155881287          ATM efficiency = 82.95%
ATM w/snap framing bytes = 5387212772   ATM w/snap efficiency = 79.38%

Funet 970608:

total packets seen = 6699991, total payload bytes seen = 2336213700
ATM framing bytes = 2783454053          ATM efficiency = 83.93%
ATM w/snap framing bytes = 2919019891   ATM w/snap efficiency = 80.03%

Pasi