I used iperf to measure the max throughput for TCP connection between two ubuntu machines. Both the machines were directly connected be means of a 1Gbps cable. When I performed iperf tests i obtained a bandwidth of 845 Mbps on an average. But when i tried reversing the direction (i.e changed server to client and viceversa) the results went down to 185 Mbps.These results are an average of ten readings and the max i was able to obtain was 370Mbps. I then decided to set the same value for parameters such as rmem_max, wmem_max, tcp_rmem, tcp_wmem but even after setting same parameters i got similiar results. i.e(845Mbps in one direction and 185Mbps in the other direction). I don't know what the possible cause could be. Is there something important that i have missed?
these are the results of netstat -in on both the systems:
Ifac MTU Met RX-ok rx-err rx-drp rx-ovr tx-ok tx-err tx-drp tx-ovr flg
eth0 1500 0 14976 0 0 0 8546 0 0 0 BMRU
eth1 1500 0 8268 0 0 0 14646 0 0 0 BMRU
netstat -in
on both machines?