Throughput Tests with ASGC
These throughput tests were done with Jason Shih, Chia Ming Kuo and
Aries Hung.
The
doIperf.sh
was run from a Linux 2.6 kernel system
Linux ce03-lcg.projects.cscs.ch 2.6.9-42.0.10.EL.cernsmp #1 SMP
Thu Mar 1 15:11:46 CET 2007 i686 athlon i386 GNU/Linux
The throughput looks much better than the one from the
test of April 30th done with the Linux 2.4 kernel system.
But a test measurement on the same Linux 2.4 system done immediately after the Linux 2.6 measurements showed the same improvements (on the
same page). The variation of the TCP congestion algorithm also has no great effect on the upload to ASGC, as can be seen from the graphs below.
Basic sysctl settings
The default tcp window size settings are much too small, so changed them to
sysctl -w net.ipv4.tcp_rmem="131072 1048576 2097152"
sysctl -w net.ipv4.tcp_wmem="131072 1048576 2097152"
sysctl -w net.ipv4.tcp_mem="131072 1048576 2097152"
sysctl -w net.core.rmem_default=1048576
sysctl -w net.core.wmem_default=1048576
sysctl -w net.core.rmem_max=2097152
sysctl -w net.core.wmem_max=2097152
Route, RTT and packet loss
HOST LOSS RCVD SENT BEST AVG WORST
148.187.33.2 0% 100 100 0.37 0.51 2.13
148.187.32.4 1% 99 100 0.10 0.21 0.55
swima2.cscs.ch 0% 100 100 0.34 2.13 162.41
swiEL2-10GE-1-4.switch.ch 0% 100 100 3.09 3.33 4.05
swiCE3-10GE-1-3.switch.ch 0% 100 100 3.84 9.98 185.01
swiCE2-10GE-1-4.switch.ch 0% 100 100 3.93 4.80 58.08
switch.rt1.gen.ch.geant2.net 0% 100 100 3.97 4.81 37.65
so-7-2-0.rt1.fra.de.geant2.net 1% 99 100 12.11 12.63 30.43
abilene-wash-gw.rt1.fra.de.geant2.net 0% 100 100 104.29 106.59 121.48
ge-1-0-0.418.rtr.chic.net.internet2.edu 1% 99 100 106.18 108.10 124.67
s4-ge-peer1.manlan-abilene.twaren.net 1% 99 100 126.76 130.56 246.96
s4-ge-chti-ir1.tpc-chi.twaren.net 0% 100 100 317.08 317.45 322.97
ascc-76-v20.twaren.net 1% 99 100 317.57 318.76 381.60
202.169.174.90 1% 99 100 315.55 317.39 438.84
202.169.174.50 6% 94 100 315.57 316.50 341.02
202.169.174.29 1% 99 100 315.54 316.77 353.03
202.169.175.101 1% 99 100 316.03 316.81 323.32
140.109.98.111 1% 99 100 315.50 316.32 323.82
Influence of TCP window size and number of parallel streams
Using the BIC congestion algorithm
From the
TCP Tuning Guide:
Starting in Linux 2.6.7 (and back-ported to 2.4.27), BIC TCP is part of the kernel, and enabled by default. ...
Starting with version 2.6.13, Linux supports pluggable congestion control algorithms
So, the default algorithm for this kernel should be BIC.
This setting should only affect the sending side.
Upload to ASGC:
Download from ASGC:
Using the Westwood congestion algorithm
TCP
Westwood algorithm was activated by
sysctl -w net.ipv4.tcp_westwood=1
This setting should only affect the sending side.
As can be seen from the upload graphs, westwood shows no improvement over BIC for this connection. It even seems to perform slightly worse.
Upload to ASGC:
Download from ASGC:
--
DerekFeichtinger - 05 May 2007