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@ivs.cs.uni-magdeburg.de. 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.