Hello World from Network Simulator

ns-3 is a fabulous network simulator. It allows you to setup a custom network environment and do experiments with it. The reason I want to play with it is to learn what TCP Tahoe differs from TCP Reno in fact (instead of in theory).

Here is a list of steps to get started with ns-3.

1. Get a Ubuntu VM

2. Install prerequisits
   a. You could follow this document for details
   b. Basically, run the following command

   sudo apt-get install gcc g++ python gcc g++ python python-dev qt4-dev-tools libqt4-dev mercurial bzr cmake libc6-dev g++-multilib gdb valgrind gsl-bin libgsl2 flex bison libfl-dev tcpdump sqlite sqlite3 libsqlite3-dev libxml2 libxml2-dev libgtk2.0-0 libgtk2.0-dev vtun lxc uncrustify doxygen graphviz imagemagick texlive texlive-extra-utils texlive-latex-extra texlive-font-utils texlive-lang-portuguese dvipng python-sphinx dia python-pygraphviz python-kiwi python-pygoocanvas libgoocanvas-dev ipython libboost-signals-dev libboost-filesystem-dev openmpi-bin openmpi-common openmpi-doc libopenmpi-dev

3. Download ns-3 sources

   cd
   mkdir workspace
   cd workspace
   wget http://www.nsnam.org/release/ns-allinone-3.26.tar.bz2
   tar xjf ns-allinone-3.26.tar.bz2

4. Build ns-3

   cd ns-allinone-3.26
   ./build.py --enable-examples --enable-tests

5. Create a hello world program

   cd ns-3.25/
   cp examples/tutorial/first.cc scratch/

   You could view the code in the end of the post.

6. Build and run the program

   ./waf
   ./waf --run scratch/first

   The output of the program will be something like the following.

   At time 2s client sent 1024 bytes to 10.1.1.2 port 9
   At time 2.00369s server received 1024 bytes from 10.1.1.1 port 49153
   At time 2.00369s server sent 1024 bytes to 10.1.1.1 port 49153
   At time 2.00737s client received 1024 bytes from 10.1.1.2 port 9

7. You can also use the Python binding to write the program. However it is still a work in progress and there are some limitations.

Sample Code

/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation;
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

#include "ns3/core-module.h"
#include "ns3/network-module.h"
#include "ns3/internet-module.h"
#include "ns3/point-to-point-module.h"
#include "ns3/applications-module.h"

using namespace ns3;

NS_LOG_COMPONENT_DEFINE ("FirstScriptExample");

int
main (int argc, char *argv[])
{
  Time::SetResolution (Time::NS);
  LogComponentEnable ("UdpEchoClientApplication", LOG_LEVEL_INFO);
  LogComponentEnable ("UdpEchoServerApplication", LOG_LEVEL_INFO);

  NodeContainer nodes;
  nodes.Create (2);

  PointToPointHelper pointToPoint;
  pointToPoint.SetDeviceAttribute ("DataRate", StringValue ("5Mbps"));
  pointToPoint.SetChannelAttribute ("Delay", StringValue ("2ms"));

  NetDeviceContainer devices;
  devices = pointToPoint.Install (nodes);

  InternetStackHelper stack;
  stack.Install (nodes);

  Ipv4AddressHelper address;
  address.SetBase ("10.1.1.0", "255.255.255.0");

  Ipv4InterfaceContainer interfaces = address.Assign (devices);

  UdpEchoServerHelper echoServer (9);

  ApplicationContainer serverApps = echoServer.Install (nodes.Get (1));
  serverApps.Start (Seconds (1.0));
  serverApps.Stop (Seconds (10.0));

  UdpEchoClientHelper echoClient (interfaces.GetAddress (1), 9);
  echoClient.SetAttribute ("MaxPackets", UintegerValue (1));
  echoClient.SetAttribute ("Interval", TimeValue (Seconds (1.0)));
  echoClient.SetAttribute ("PacketSize", UintegerValue (1024));

  ApplicationContainer clientApps = echoClient.Install (nodes.Get (0));
  clientApps.Start (Seconds (2.0));
  clientApps.Stop (Seconds (10.0));

  Simulator::Run ();
  Simulator::Destroy ();
  return 0;
}