NetBSD ECN implementation test results

Two machines were used for this test, both with ECN end-host support. The objective was to measure the number of drops in an ECN environment. This is a simple implementation test and doesn't evaluate the value of ECN. There are several papers out there with that information.

tcpdump(8) was used to capture the traffic, ttcp(1) to do the benchmarks and ethereal(1) to analyze the traffic. altq(9) was used with RED and ECN router support.

ALTQ interface was configured for RED/ECN operation at 3Mbps (the wire speed is 10Mbps) with:

interface le0 bandwidth 3M red ecn

Non-ECN test

tcpdump file is non-ecn.cap.

ttcp-r: buflen=8192, nbuf=2048, align=16384/0, port=5001  tcp
ttcp-r: socket
ttcp-r: accept from 10.0.0.16
ttcp-r: 16777216 bytes in 77.50 real seconds = 211.41 KB/sec +++
ttcp-r: 11383 I/O calls, msec/call = 6.97, calls/sec = 146.88
ttcp-r: 0.0user 0.3sys 1:17real 0% 0i+0d 0maxrss 0+2pf 11379+25csw

Analysis (by Ethereal)

Previous segment lost: 69
Suspected Fast-Retransmissions: 50
Window updates: 91
Suspected Retransmissions: 19

Throughput

ECN test

tcpdump file is ecn.cap.

ttcp-r: buflen=8192, nbuf=2048, align=16384/0, port=5001  tcp
ttcp-r: socket
ttcp-r: accept from 10.0.0.16
ttcp-r: 16777216 bytes in 46.76 real seconds = 350.37 KB/sec +++
ttcp-r: 11588 I/O calls, msec/call = 4.13, calls/sec = 247.81
ttcp-r: 0.0user 0.3sys 0:46real 0% 0i+0d 0maxrss 0+1pf 11587+6csw

Throughput

Analysis (by Ethereal)

Previous segment lost: 0
Suspected Fast-Retransmissions: 0
Window updates: 0
Suspected Retransmissions: 0

Which means, no dropped packets.
$Id: testresults.html,v 1.2 2006/07/23 18:02:42 goteki Exp $