netperf on RPI

[Norman Feske]

Hello Mohammad,

> I am still getting same small numbers for the throughput when testing
> the network performance for the Raspberry pi  with the TCP_STREAM,

the small TCP window size you observed seems to be the limiting factor.
But I have no idea why the TCP connection throttles the window
parameters in this way.

Have you tried any of the following experiments to encircle the problem?

* Different host machine
* Different OS on your host machine. You mentioned that the problem
  does not occur when running OpenBSD in a VM on the host machine.
  How is the behavior when running OpenBSD natively on the host machine?
* Different network equipment (network cables, switch)
* Different Raspberry Pi
* Different power supply for the Raspberry Pi
* Performing the netperf test with Raspian

> could you tell me please what you use in the  client machine side,

We run our nightly tests on Ubuntu 12.04.4 LTS (GNU/Linux
3.2.0-67-generic x86_64).

Have you tried to follow (and possibly instrument) the lwIP code that is
involved in the TCP parameter negotiation?

Cheers
Norman

-- 
Dr.-Ing. Norman Feske
Genode Labs

http://www.genode-labs.com · http://genode.org

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