Network Simulator (NS) Intro

Installation

You can find an all-in-one installation packet in http://www.isi.edu/nsnam/ns/ns-build.html#allinone. It contains the source code and any other tools required by the simulator.

ns-allinone-2.1b7a

This release does not work out of the box in FreeBSD 2.2.8. Apply the patch in /usr/dirt/src/ns before you run ./install:

% cd ~ns-allinone-2.1b7
patch < patch.ns-allinone-2.1b7a.FreeBSD.2.2.8

Learning NS

I have some suggestions for anyone that wants to learn NS:

• Read Marc Greis's tutorial (http://www.isi.edu/nsnam/ns/tutorial/index.html)
• Read WPI's tutorial (http://perform.wpi.edu/NS/index.html)
• Refer to NS Manual (http://www.isi.edu/nsnam/ns/ns-documentation.html) for more details, but be careful, since it is not complete and it does not keep up with the changes in the code. The ultimate reference is always the source code, so it is critical to understand the general architecture of the simulator.
• Learning by example is the most common technique. NS includes tons of them in ~ns/tcl/ex and ~ns/tcl/test (Hint: use grep -R to find examples of whatever you're interested in.)
• Search NS mailing list (ns-users@isi.edu), and ask questions in ns-users. There are three or four experts that regularly answer questions and some advance users also help (I do). Additionally, patches are first posted here, and it takes a while for them to be applied, so it is a good idea to be subscribed and read the messages. Traffic is not too bad (5-20 messages each day.)
• Be patient: NS is frustrating. It is a large project with many contributors, and it is plenty of arbitrary/temporary implementation decision. However, it is a really powerful research tool, the general design is very good, and you can learn a lot about networking using it.