iptables throughput on Soekris net4801

Earlier today I had to find out what the capacity of a soekris net4801 running openwrt.

Using a fairly normal rule set, it can forward 51.8 Mbits/sec which is alright for a 266 MHz processor.

Sadly for me, we’ll be getting a 100 Mbit fiber optic connection at work in a few months, so I guess I’ll have to move to a net5501 unit in order to max out the connection.

Output from iperf -s (second run is over the lan):

------------------------------------------------------------
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
------------------------------------------------------------
[  4] local x port 5001 connected with x port 64183
[ ID] Interval       Transfer     Bandwidth
[  4]  0.0-10.0 sec  61.7 MBytes  51.7 Mbits/sec
[  5] local x port 5001 connected with x port 64184
[  5]  0.0-10.0 sec  1.07 GBytes    921 Mbits/sec

Output from iperf -c:

------------------------------------------------------------
Client connecting to x, TCP port 5001
TCP window size:   129 KByte (default)
------------------------------------------------------------
[  3] local x port 64183 connected with x port 5001
[ ID] Interval       Transfer     Bandwidth
[  3]  0.0-10.0 sec  61.7 MBytes  51.8 Mbits/sec