Reciever:

TCP buffer size:

echo "4096 87380 128388607" > /proc/sys/net/ipv4/tcp_rmem
echo "4096 65530 128388607" > /proc/sys/net/ipv4/tcp_wmem

echo 128388607 > /proc/sys/net/core/wmem_max
echo 128388607 > /proc/sys/net/core/rmem_max

/sbin/setpci -d 8086:1048 e6.b=2e

[root@w02gva add]# ./iperf-1.6.5 -s -w 128M
------------------------------------------------------------
Server listening on TCP port 5001
TCP window size:  256 MByte (WARNING: requested  128 MByte)
------------------------------------------------------------
[  6] local 192.91.239.213 port 5001 connected with 198.51.111.90 port 32848
[ ID] Interval       Transfer     Bandwidth
[  6]  0.0-180.1 sec  49.3 GBytes  2.35 Gbits/sec

CPU load CPU0 : 50 %
         CPU2 : 15 %

Sender:

/sbin/ifconfig eth1 txqueuelen 10000
/sbin/ifconfig eth1 mtu 9000

Before all new connections:
sysctl -w net.ipv4.route.flush=1

[root@cit-slac19 fc]#iperf -c 192.91.239.213 -i 5 -P 3 -w 40M -t 180

CPU load CPU0 : 30%
         CPU2 : 70%


dmp file: dmp_cern_snv_2.35_180s_2.txt