NS2 Download

NS2 download 

In this section we are going to discuss about the basics of ns2.Example program for network simulator 2.Ns2 is a open source software and can be freely downloaded and utilized for Research Purpose.

Quick Intro about NS2 ( Ns2 simulator):

• NS2 is a discrete event simulator targeted at networking research.
• NS2 is an object oriented simulator, written in C++, with an OTcl interpreter as a frontend.

Ns2 basics:

• NS2 use Tcl language for creating simulation scenario file.
• Network topology, transmission time, using protocol etc are defined in scenario file

Steps involved in creating scenario file:

Step0 Declare Simulator and setting output file

Step1 Setting Node and Link

Step2 Setting Agent

Step3 Setting Application

Step4 Setting Simulation time and schedules

Step5 Declare finish

 

Sample code for ns2:

This is the sample code for creating random traffic in wireless network.

ns cbrgen.tcl [-type cbr|tcp] [-nn nodes] [-seed seed] [- mc connections] [-rate rate]

 

What are the return commands are used in ns2:

#define TCL_OK 0

#define TCL_ERROR 1

#define TCL_RETURN 2

#define TCL_BREAK 3

#define TCL_CONTINUE

TCL_OK: it denoted command completes successfully

TCL_ERROR: it implies does not complete successfully. The interpreter will explain thereasons for the error.

TCL_RETURN: after returning from c++, the interpreter exits the current instproc without performing the rest of instproc.

TCL_BREAK: After returning from C++, the interpreter breaks the current loop. This is similar to executing C++ keyword break, but the results prevail to the OTcl domain

TCL_CONTINUE: After returning from C++, the interpreter continues to the next iteration. This is similar to executing C++ keyword continue, but the results prevail to the OTcl domain.