TCPTuner is TCP congestion control kernel module and GUI packaged together. By loading our kernel module (which is essentially a clone of CUBIC), and running the GUI, users can adjust several parameters of the CUBIC congestion control algorithm.
See the TCPTuner Paper (PDF) for more information about the background, implementation, and contributions of TCPTuner.
How to Build and Load the Kernel Module
cd module/ make sudo rmmod tcp_tuner.ko sudo insmod tcp_tuner.ko sudo sysctl -w net.ipv4.tcp_congestion_control=tuner
The TCPTuner GUI
sudo apt-get install qt5-qmake qt5-default
To Build and Run
cd gui/TCPTuner/ qmake make sudo ./TCPTuner
TCPTuner exposes the parameters of TCP CUBIC to the user via the TCPTuner GUI. The parameters present in TCP CUBIC, along with their descriptions and default values are in the table below.
|alpha||Scales W_max, which adjusts the rate at which cwnd grows after a loss event||512|
|beta||beta for multiplicative decrease||717|
|fast_convergence||turn on/off fast convergence||1|
|tcp_friendliness||turn on/off tcp friendliness||1|
Additonal Parameters from ip-route
The TCPTuner GUI also provides access to the following
ip route parameters. The GUI will apply these
ip route parameters to all of the routes in the routing table.
|rto_min||the minimum TCP retransmission timeout to use when communicating with this destination.||None|
|initcwnd||the initial congestion window size for connections to this destination. Actual window size is this value multiplied by MSS.||0|
MahiMahi Simulation Environment
This repository also contains a MahiMahi simulation environment so that users can see the impact of TCP congestion control parameters.
First, you must install MahiMahi:
sudo add-apt-repository ppa:keithw/mahimahi sudo apt-get update sudo apt-get install mahimahi
Before you can run MahiMahi, you must set ip_forward=1
sudo sysctl -w net.ipv4.ip_forward=1
Now, tcp_tuner should be set as the congestion control algorithm.
Single Flow, Tail-drop Buffer
The first simulation shows throughput and delay of a single TCP flow on a 12Mbps uplink.
cd mahimahi/ ./start_all
Two Flows Sharing Bottleneck
The second simulation shows throughput graphs of each flow sharing a bottleneck link. This can be used to compare default cubic to tcp_tuner.
cd mahimahi/ ./start_shell
Now that the bottleneck link is created, we can run multiple clients within that shell.
./start_client 5050 1 & <-- creates an tuner client in a new process ./start_client 5050 0 & <-- creates a cubic client in a new process
To close these
fg <--to bring one of the kid process to the foreground Ctrl+C (repeat for each client) exit <-- to exit the shell