Implementation of T-DCTCP in ns-3

Course Code: CO365

Assignment: #20

Overview

The assignment involves implementing modifications mentioned in the T-DCTCP paper [1] in ns-3 [3]. The modifications are as follows:

[1] Increasing cwnd when ECE = 0 in Congestion Avoidance algorithm.

[2] Resetting alpha (Congestion Indicator) to zero once Delayed Ack Timeout Event occurs.

[3] Dynamic calculation of Delayed Ack Timeout.

How to compile and run

Clone the repository

git clone https://github.com/Akshay6697/Modification-of-DCTCP.git

Build ns-3 with examples and tests

cd Modification-of-DCTCP
./waf configure --enable-examples --enable-tests
./waf build

How to run test case

./waf --run "test-runner --suite=tcp-dctcp-test"

Note: Testcases to test the modifications of T-DCTCP are added in same the test case file as for DCTCP.

How to run Example

./waf  --run "dctcp-example --pathOut=scratch --writeForPlot=0 --writePcap=1"

Note: While running the example, the user can set the following variables

  1. pathOut - Path to save results from --writeForPlot/--writePcap
  2. writeForPlot - <0/1> to write results for plot (gnuplot)
  3. writePcap - <0/1> to write results in pcapfile

References

[1] Tanmoy Das and Krishna M. Sivalingam, "TCP improvements for data center networks"

[2] RFC 8257- Data Center TCP (DCTCP): TCP Congestion Control for Data Centers

[3] The ns-3 network simulator. http://www.nsnam.org/

[4] RFC 2001- TCP Slow Start, Congestion Avoidance, Fast Retransmit, and Fast Recovery Algorithms