Network Simulator

discrete event  network simulator.

•It runs on Linux, FreeBSD, Solaris, Mac OSX and on Windows using Cygwin .

•It is built in C++ and provides a simulation interface through Otcl and by VINT.

Working Flow

•NS – Network Simulator

•NAM- Network AniMator –demonstrate the visual output

•Preprocessing-handwritten Tcl or topology generator

•Post analysis-

•Trace analysis using Perl/TCL/AWK/MATLAB

•Network component objects in the data path are written and compiled using C++

•Otcl creates matching objects ,control function & configurable variable  from C++ output

Steps in Simulation

•Create event Scheduler

•Trace packets in all links

•Create network

•Create transport connection

•Create traffic over transport connection

•Transmit application level data.