contact@emark-technologies.com
+91-7349129212
contact@emark-technologies.com
+91-7349129212
Setting up a network to do some real experiments is the best way for studying about communication in internet. However, setting a network is not easy and costly. For this reason, a virtual network provided by network simulator is used for experiment in only one computer. Specially, NS2 which is free and easy to use is the popular all over the world.
NS2 use Tcl language for creating simulation scenario file (for example, sample.tcl). Network topology, transmission time using protocol etc. are defined in scenario file. If we execute this scenario file, the simulation result will be output to out.tr and out.nam file.
out.tr all the information about communication is written in this file. We can find out the way a packet was forwarded. This file is called as trace file.
out.namcontains the data for animation of the experiment result. This file can be executed by Nam, an animation software. The state of forwarding packet in Nam.
If simulation use TCP, we can also observe the state of TCP congestion control by a trace file. out.tcp Record the change of TCP parameters by time. Using Gnuplot software to plot a graph, it is easy to observe the appearance of congestion control. This file is called as TCP trace file.