Forschung : Projekte : NS-2 Emulation Extensions

Introduction

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.

We 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.

Documentation

• Single Host User Guide [PDF] [Postscript]
• Distributed Clients User Guide [PDF] [Postscript]

Papers

• Daniel Mahrenholz and Svilen Ivanov, "Real-Time Network Emulation with ns-2", Proceedings of The 8-th IEEE International Symposium on Distributed Simulation and Real Time Applications, Budapest Hungary, October 21-23, 2004.
• Daniel Mahrenholz and Svilen Ivanov, "Adjusting the ns-2 Emulation Mode to a Live Network", KiVS'05, Kaiserslautern Germany, 28.02. - 03.03.2005.

Downloads

• Single Host Emulation Patch against ns-2.28 and ns-2.29, examples [TGZ][ZIP]
• Single Host Emulation binary and source packages for Debian are available from the repository:
  deb http://bode.cs.uni-magdeburg.de/~aherms/debian sid ns2
  deb-src http://bode.cs.uni-magdeburg.de/~aherms/debian sid ns2
  The name of the package is nsemulation.
• Distributed Clients Emulation Patch against ns-2 2.27, examples [TGZ]
• Precompiled 2.6.1-uml kernel [GZ]
• Precompiled 2.6.1-uml-tapmtu kernel [GZ]
• TAP-MTU-Patch [DIFF] (for Linux kernel 2.4.21+ and 2.6.x)

Contact

All questions and remarks regarding this webpage should be send to mahrenho. All other questions (e.g. support requests, bug reports) should be send to our NSE mailing list. If you like to join the mailing list go here.