From: Gabriel Paues <gabriel@si...> - 2002-08-07 15:04:53
I try to test how a Token Bucket Filter shapes the traffic, in a virtual
network consisting of 2 UML-instances, host1 and host2.
I setup a TBF on the eth-interface that connectect host2 to host1:
> tc qdisc add dev eth1 root tbf rate 300kbit latency 50ms burst 4096
I also have put a tcpdump on host2 to be able to calculate the throughput
after the tbf. Then I transmit some data with FTP between the UMLs.
The TBF does shape the traffic, but not at the rate I have set it to.
Instead the transmission-rate after the filter is 800kbit.
I assume that this has to do with some timing issues in TBF. Maybe it
calculates its rate from the cpu-speed from /proc/cpuinfo in the UML.
If anyone had an idea I would be really happy!