An NS2 TCP Evaluation Tool: Installation Guide and Tutorial

A TCP performance evaluation tool for the network simulator NS2 has been developed. This document describes how to install and use this tool.

Researchers frequently use the network simulator NS2 to evaluate the performance of their protocols in the early stage of design. One particular area of recent intest is the congestion control protocols (a.k.a., TCP alternatives) for high-speed, long-delay networks. There is significant overlap among (but lack of a community-agreed set of) the topologies, traffic, and metrics used by many researchers in the evaluation of TCP alternatives: effort could be saved by starting research from an existing framework. As such, we developed a TCP performance evaluation tool. This tool includes several typical topologies and traffic models; it measures some of the most important metrics commonly used in TCP evaluation; and it can automatically generate simulation statistics and graphs ready for inclusion in latex and html documents. The tool is very easy to use and contains an extendable open-source framework.

This tool can be used not only for high-speed TCP protocols, but for other proposed changes to congestion control mechanisms as well, such as ECN added to SYN/ACK packets, changes to make small transfers more robust, changes in RTO estimation, and proposals to distinguish between loss due to congestion or corruption, etc.

tags : tcp evaluation tool ns2 network simulator

NS-2 Emulation Extensions

The network simulator ns-2 is a widely accepted discrete event network simulator, actively used for wired and wireless network simulations. It has a highy detailed model of the lower layers (Physical and MAC) of wireless IEEE 802.11 networks.

Ns-2 has also an emulation feature, i.e. the ability to introduce the simulator into a live network and to simulate a desired network between real applications in real-time.

Within the scope of this project we developed some methods and extensions to the ns-2 to combine wireless network simulation and network emulation. Now ns-2 can emulate an arbitrary IEEE 802.11 network between real applications. Furthermore, our extensions are generic, i.e. can be applied to any network supported in the ns-2.

NS-2 emulation extensions use two methods for network emulation: Single Host and Distributed Clients. In the first method the simulator and all the applications run on one computer. We use User-Mode-Linux virtual machines and emulate a ns-2 netwok among them. The applications run inside the virtual machines and do not notice that they communicate through a simulated network.

In the Distributed Clients method we run the applications and the simulator on separated machines for better scalability. Here we use TUN/TAP virtual network interfaces and map them to nodes in the ns-2 simulator. The network among these TUN/TAP interfaces is again simulated. The applications interact with it in the same way they would interact with a real network.

More Info.

tags : network simulator ns2 emulation extension physical layer MAC wireless

Extended Network Simulator NS-2 Nam Editor

The Extended Nam Editor is an editor that allows the graphical creation of ns2 scripts. It extends the basic Nam Editor with the following features:

1. Integration with existing topology generators
2. Localization and visualization of set of nodes on large network topologies according to different selection criteria;
3. Instantiation of agents of any types on all the nodes of a given node set;
4. Definition of new node types;
5. Support for simulations of web cache systems.

Topology Generator Interface
The manual generation of complex Network Topology is a tedious and error prone activity.

In order to simulate networks with realistic topologies, it is a common practice to use ad-hoc topology generators, whose output is usually not compatible with the ns2 syntax. Hence, several tools have been developed to translate topology descriptions generated by topology generators in ns-scripts that can be used in the definition of a simulation scenario.

Unfortunately, scripts produced in this way are not compatible with the Nam Editor, hence networks created by common topology generators cannot be modified interactively. Such a limitation is sometimes annoying, in particular when the automatically generated topology needs to be further adapted, e.g. by instantiating agents on particular network nodes.

Nam-Editor provides a graphical interface to:

• GT-ITM topology generator;
• INET topology generator;

It is now possible to create, visualize and modify topologies created according to the following topology models:

1. flat-itm;
2. hierarchical-itm;
3. transit-stub-itm;
4. INET;

More info here

tags : network simulator ns2 topology generator gt-itm inet nam editor

Related Articles : NS WorkBench : Graphical User Interface For Network Simulator ns2measure : An Integrated Framework for Enabling Effective Data Collection and Statistical Analysis with ns2

ns2measure : An Integrated Framework for Enabling Effective Data Collection and Statistical Analysis with ns2

The Network Simulator 2 (ns2) is an open source tool for network simulation. When planning for large-scale simulation experiments, an efficient and flexible data collection and a statistically sound output data analysis are important aspects to keep in mind. Unfortunately, ns2 offers little support for data collection, and statistical analysis of the simulation results is most often performed offline, using either home made code or available packages, which are not integrated with ns2.

In this site, you will find two complementary contributions:

• the first one consists of a set of C++ modules, that allow a flexible and efficient data collection;
• the second one is a software framework, which is fully integrated with ns2, which performs all the operations required to carry out simulation experiments in a statistically sound way.

To learn more about ns2measure, link

Reference :
An Integrated Framework for Enabling Effective Data Collection and Statistical Analysis with ns2
Claudio Cicconetti, Enzo Mingozzi, Giovanni Stea,
Workshop on ns-2: the IP network simulator (WNS2)
Pisa, Italy, October 10, 2006.

tags : ns2measure ns2 network simulator data collection statistical analysis

Related Articles : Why the simulation results are not stable? NS WorkBench : Graphical User Interface For Network Simulator

NS WorkBench : Graphical User Interface For Network Simulator

nsBench is a drag-and-drop GUI and easy to use in undergraduate and graduate networking courses. nsBench makes NS-2 simulation development and analysis faster and easier for students and researchers without losing the flexibility or expressiveness gained by writing a script.

nsBench v1.0 features include :

• Nodes, simplex/duplex links and LANs
• Agents: TCP, UDP, TCPSink, TCP/Fack, TCP/FullTcp, TCP/Newreno, TCP/Reno, TCP/Sack1, TCPSink, TCPSink/Sack1, TCPSink/DelAck, TCPSink/Sack1/DelAck, TCP/Vegas, Null Agent
• Applications/Traffic: FTP, Telent, Http/Server, Http/Client, Http/Cache, webtraf, Traffic/CBR, Traffic/Pareto, Traffic/Exponential
• Services: Multicast, Packet Scheduling, RED, DiffServ
• Creating "Groups" concept to compensate for "loops"
• Scenario generator
• Link Monitors
• Loss Models
• Routing Protocols

Learn more of nsbench

tags: nsbench, graphical, user, interface, network, simulator, ns2

Research Tool : CiteuLike (Updated)

I found this great site for research, CiteULike. (link to my CiteULike library)



CiteULike is a free service to help academics to share, store, and organise the academic papers they are reading. When you see a paper on the web that interests you, you can click one button and have it added to your personal library. CiteULike automatically extracts the citation details, so there's no need to type them in yourself. It all works from within your web browser. There's no need to install any special software.

Because your library is stored on the server, you can access it from any computer. You can share your library with others, and find out who is reading the same papers as you. In turn, this can help you discover literature which is relevant to your field but you may not have known about.

Give it a try here.

Tags : research tool citeulike ns2 network simulator