[nsp] Throughput of 100 Mbps
tbaranski at mail.com
Fri Nov 7 11:12:18 EST 2003
> You are raising a very interesting question. I never understood
> (or seriously tried to understand) what is meant by this
> throughput numbers.
> Are you saying that the pps numbers from Cisco are always for
> 64-bytes packet? Could be, in fact this gives the highest pps
> number... And it's always one-way, right?
Cisco's numbers are all for 64-byte packets to my knowledge, as are most
pps numbers from other vendors. I don't know whether or not the tests
are run with a unidirectional flow, but it may not matter from the
router's perspective -- the router is just forwarding packets,
regardless of direction.
> The test I made was very simple: a 3620 with 2 FE interfaces,
> and a PC on each of those; then FTP between the two PCs.
> I only had 40% of CPU usage - why isn't it trying harder, to
> reach a higher throughput? :-)
I suspect if you ran a dedicated bandwidth testing program like TTCP
you'd get a higher number. (Applications aren't always able to achieve
100% throughput on any given end-to-end link.) When saturated, my
experience is that the router's CPU will max out in interrupt context if
CEF is enabled.
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