An overview of network simulators
What is network simulator?
In network research area, it is not feasible and it is very costly to get a network bed for test and analysis. For the same reason network simulators are getting popular.
Network simulator is a software which simulates the behavior of network. It simulates the network either by capturing data packets or by using some mathematical formula. It can simulate the network behavior with different environment and different networks with the different attributes of the network, hosts, applications and services. In the simulation the environment and the attributes of the different can easily be modified.
Network simulators cover wide range of applications, protocols, networks and different traffic scenarios.
Most of the network simulator software uses GUI to ease the operation for the user. It helps in analyzing the behavior of the network by the simulating software.
Network models define the network entities like hubs, switches, routers links etc and the events (data transmission, packet flow, errors etc.). As output of the simulation we get a trace file which is analyzed to get the overall performance of the network.
Most simulators are event driven simulators. The events are stored in a file. They are used or executed in the order in which they are stored.
Network Simulating Softwares
Some popular network simulators available are:
- NS ( Open Source )
Required platforms to use network simulators
- Linux ( FreeBSD and Debian )
- Unix and Unix Like Systems
- Windows 95 or higher
Types of Network Simulators
- 1. Commercial and Open Source
To get commercial simulators some amount is to be paid. Advantage of commercial simulators is that, for this software we can get full support from the vendors. We will get full documentation on the software. Example of commercial simulators is OPNET and NetSim. They support wide range of modules.
In contrary, open source are those which are freely available and we don’t need to pay.. But the open sources have got some limitations. They are limited to some modules. It is difficult to get full documentation for the software.
- 2. Simplex and Complex
Simplex simulators are useful for simple networks. They can show how packet goes from one node to another etc. They are very simple. But complex simulators facilitates us to analyze the data, traffic analysis, design new protocols etc..
Use of Network Simulators
Simulator is useful when a new network layout is to be designed. The simulators are very fast and inexpensive. So to implement a new network layout first the entire network can be designed using the network simulators with several computers, routers, hubs, and switches and if there is any problem with the network layout then from the simulator it can be detected and can be solved. It is also helpful to the researchers to who are designing new protocols.