NetSim – A look at the simulation config file

Sophisticated users model their simulation via a config file that is independent of the GUI. The config file contains all required information to run the simulation including the network topology, devices, links, traffic, statistics, traces etc. Given below are important features of NetSim’s config file:

Model in XML format

Unlike, traditional simulators that use a flat text file, NetSim uses XML format given its advantages.

a. Quicker Understanding: It is easier to understand what the document holds at a glance and has moreprecise declarations of content allowing for more meaningful search results

b. Better Presentation: XML enables the separation of presentation from data and is suitable as a description for complex hierarchical data as is typical in a simulation config file

c. Automatic Format Verification: MSVC allows you to switch between XML view and Data View, and helps to locate syntax error. The schema we provide along with enables statement completion feature, as well as an option to validate the XML data.

Mirror Real Networks

Various network technologies are supported including LAN, WAN, PAN, WSN, Mobile, Cellular, Wireless and Inter-network.

Devices are modeled per the 5 layer TCP / IP stack. Users can set protocol properties in each of these layers in all devices.

Traffic can be configured as applications like FTP, Database, Voice, Video etc. Further, lower level mathematical distributions are available for packet size and inter-arrival time for users to model custom apps.

And finally, the config file provides a simple interface for linking external libraries.

Log traces and analyze metrics

The config file allows you to choose end-to-end metrics you wish to analyze and traces you want to log. A range of statistics is available including throughput, utilization, delay, error, loss etc. The packet trace can be logged in .txt or .csv format and an event trace can be generated for those using our debug libraries.

TETCOS Releases NetSim v 6.2

TETCOS is pleased to announce the latest release of Network Simulation Software, NetSim ver 6.2, which comes with several new and exciting features. Given below is a quick snapshot:

All new license roaming

Increasingly, users want to take their work “on the road.” NetSim now provides built-in license roaming capability allowing users to check out a license from a server, physically disconnect from the server and continue to use the license for a period of 24 hours after which the license is automatically returned to the server when it expires on the mobile computer.

Additional platforms and java language support

v 6.2 has been tested on 32 and 64 bit Win OS: XP, Vista, 7 and beta tested on Win 8.

In addition to C & C++ with v6.2 NetSim programming exercises now support Java based user codes.

Easier coding – More API’s and simpler debug

Several API’s have been added  in the standard version. These include RIP’s Distance Vector algorithm, Periodic, Expiration and Garbage Timers and OSPF’s Hello Packets, LSA Packets, Designated Router Selection, LSDB Formation and Djikstra’s Algorithm

All codes now take install directory and windows temp folder as Command line arguments and NetSim programming exercises now allow you put break points in your code and de-bug in runtime

IIT Kharagpur Licenses NetSim

TETCOS is happy to announce the Indian Institute of Technology (IIT) Kharagpur has licensed NetSim.

IIT Kharagpur’s motivation to License NetSim

IIT Kharagpur evaluated several competitive & open source network simulators available. They focused on level of end-user friendliness, product flexibility and technical support. Flexibility was important since their students wanted to write, link and de-bug customized code for project work. Direct technical support from the developer (and not the distributor), in terms of on-site support, telephone and e-mail support, from experienced developers, was paramount to IIT Kharagpur. In both these aspects, NetSim stood out in comparison to other simulators.

Perpetual Floating License

IIT Kharagpur also wanted the perpetual floating license option available with NetSim. The floating license option offers several advantages. First, the NetSim client licenses are not tied to any one computer. Second, the license server is also not tied to any server / computer but rather tied to a USB / Parallel port dongle. And finally, any number of NetSim client installations can be carried out. Only simultaneous running of NetSim clients is checked against the number of licenses purchased.

This means there is no effort required to move the license to a new computer or even move the license server & clients to a completely new lab. The perpetual license implies that there is no expiry date on the licenses and that IIT Kharagpur can upgrade NetSim to newer releases.


It has taken Tetcos eight years to get our first IIT to license NetSim. We wanted to take a moment to thank all our customers and partners for making NetSim successful.

Today, over 250 institutions now actively use NetSim, including BITS Pilani: Hyderabad Campus, Delhi Technical University (previously DCE), NIT Rourkela, NIT Jamshedpur, NIT Suratkal, NIT Surat, NIT Bhopal, NIT Kurukshetra and NIT Durgapur.

TETCOS releases NetSim ver 6

TETCOS is happy to announce the latest release of Network Simulation Software, NetSim ver 6, which comes with several new and exciting features –

1. New Protocols: Wireless Sensor Network, Zigbee, CDMA and GSM

2. Sample Projects: Over 50 sample projects with C source code are available based on international papers. These serve as a guide for students to complete their term projects using NetSim.

3. Simulation API’s: NetSim features a set of library functions of carefully designed protocol primtives which serve as the protocol and simulation API’s. These library functions come with source code, can be called into the development environment and linked to run the protocol. Examples of library functions available in WSN include route formation, route reply, route error, slotted and unslotted CSMA, GTS, CCA, super frame formation, beacon transmission, phy layer and agent models.

4. Programming Language: NetSim’s development environment and primitive API’s are designed for users to write their codes in C. Users need not learn scripting languages, C ++, Java etc

5. Debugging Capability: A simulation can be started and then at user determined break points in the code users can perform debug using single-step, step-over, step-out and continue etc. This can be carried out at various abstraction levels, based on where the user code links, including at a per-packet level

Currently, NetSim is being actively used in over 250 institutions across the world and is featured with the book Computer Networks and Internets, V Edition, by Dr. Douglas Comer of Purdue University.