Details for traffic shaping are in http://lartc.org.

Details regarding tcp testing are here: http://www.linuxfoundation.org/collaborate/workgroups/networking/tcp_testing.

The network throughput analysis is done with different tools.

• iperf Performance Measurement
• Wireshark Packet Tracing
• netem Network emulation
• tcp_probe Kernel module (see tcp_probe.c

sudo apt-get install git iperf wireshark gnuplot

Setup a server on one computer

iperf -s

Run a client on a second computer. The client will send data to the server.

iperf -c SERVERIP -i 1

Option -i will show intermediate bandwidth results every second.

In the following example an additional 100 ms delay to the outgoing traffic is added.

sudo tc qdisc add dev eth0 root netem delay 100ms

Show the current traffic shaper

tc qdisc show

Remove a traffic shaper

sudo tc qdisc del dev eth0 root

For limiting the bandwidth a token bucket shaper can be used. In the example below the packet is delayed by 100 ms with the netem shaper and the goes to the token bucket shaper. See http://lartc.org/howto/lartc.qdisc.classless.html#AEN690.

sudo tc qdisc add dev eth0 root handle 1: netem delay 100ms
sudo tc qdisc add dev eth0 parent 1:1 handle 10: tbf rate 256kbit buffer 1600 limit 300
tc -s qdisc