Re: Send and Recv. socket buffer sizes..

Rick Jones (
Tue, 02 Nov 1999 15:17:42 -0800

Ganesh Ramasivan wrote:
> Hello,
> I don't understand why there is a difference between the send and
> receive socket buffer sizes when using netperf.
> Recv Socket Size (bytes) Send Socket Size (bytes)
> 16616 16192
> 33232 32768
> 65928 65536
> 131320 131072
> 262640 262144
> I am using netperf over myrinet which has a MTU of 3752 bytes.

I think you will find that the UDP tests may pad the recv socket buffer
so there is enough space for the addressing information returned through

What tests are you running? It would help in the explanation if you
could include some actual netperf output. Please include the command
lines so we can see if you are also setting socket buffer sizes
explicitly, or accepting defaults and such.

rick jones

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