NS3 Simulation

This repo contains a single simulation environment developed using the NS3 network simulation tool. This single cpp file contains all the functions needed to setup the topology, create all the components needed, run the simulation and collect logs. The main idea here is to let a TCP "Sender" read an external file with some information regarding the size of the next packet to be sent and the timeout to wait and then send it. In exchange, the TCP "Receiver" waits for the packet to arrive, saves the time of arrival and sends a feedback packet back to the Sender in order to certify the receiving time. In order to increase the amount of noise and simulate some network congestion, it is possible to use the --interference option and generate some UDP and TCP noise on the network. Everything is logged and can be easily plotted. Check the topology below to better understand what happens and where.

Topology

================== NETWORK SETUP ===========================
*
*  [10.1.5.0] (wifi)                    n2 -> TS
*                                      /
*  *    *    *    *                [10.1.2.0] (ptp)
*  |    |    |    |   [10.1.1.0]     /
* n5   n6   n7   n0 -------------- n1-[10.1.3.0]--n3 -> IUS
* ITC  IUC  TC   AP      (ptp)       \
*                                  [10.1.4.0] (ptp)
*                                      \
*                                       n4 -> ITS
*
* ITC/S: Interference TCP Client/Server - WifiSTA
* IUC/S: Interference UDP Client/Server - WifiSTA
* TC/S: Test Client/Server - WifiSTA
* AP: Access Point
============================================================

In the case represented here, n2 represents the Test Server and it is accessed by n7, the test client. However, in order to create some noise, a set of Server/Clients both in TCP and UDP are created and deployed over some nodes. By means of the tracking system of NS3, it is possible to log the interactions and also see an interactive visual representation of the situation. The Receiver, once the packet is received, sends a packet back to the server with the info about when the packet was received. In this way further analysis can be carried out.

Running

A working installation of NS3 has to be deployed on the machine. Check the NS3 Docs page for more info regarding the initial setup. Once the setup is ready:

1. Export NS_LOG variable
   export NS_LOG=WIFI_TCP_simulation=level_info

2. Launch as:
   RUN AS = ./waf --run "WIFI_TCP_simulation --filein=schedfile --tracing --interference

As you can see an input file is needed. You may use the one provided for testing purposes.

Waff Hack

Potentially it is also possible to use an in BASH function to launch the simulation. To do this, you have to define a function like this:

function waff() {
    CWD="$PWD"
    cd $NS3DIR >/dev/null
    ./waf --cwd="$CWD" "$@"
    cd - >/dev/null
}

export -f waff

With waff launch as:
waff --run "WIFI_TCP_simulation --filein=s --tracing --interference"

VALGRIND

For debugging purposes, I suggest using valgrind with the following launch command:
waff --run WIFI_TCP_simulation --command-template="valgrind --leak-check=full --track-origins=yes --show-leak-kinds=all %s --filein=schedulefile"

GDB

If you want to use gdb, this is the way to do it:
waff --run WIFI_TCP_simulation --command-template="gdb --args %s --filein=schedulefile"

Licensing

License

The whole repo is covered by a GNU GPL v3 license.

Author

Copyright (c) 2018 - libremente
<surf> AT <libremente> DOT eu