The Network Simulator Version 3
    -------------------------------

Table of Content:
-----------------

1) An Open Source project
2) An overview of the ns-3 project
3) Building ns-3
4) Running ns-3
5) Working with the development version of ns-3


1) An Open Source project
-------------------------

ns-3 is an Open Source project and we intend to make this
project a successful collaborative project: we hope that 
the missing pieces of the models we have not yet implemented
will be contributed by the community in an open collaboration
process.

Contributing to the ns-3 project is still a very informal
process because that process depends heavily on the personality
of the people involved, the amount of time they can invest
and the type of model they want to work on.

Despite this lack of a formal process, there are a number of 
steps which naturally stem from the open-source roots of the
project. These steps are described in doc/contributing.txt

2) An overview of the ns-3 project
----------------------------------

This package contains the latest version of ns-3 which is aims 
at being a replacement for ns-2. Currently, ns-3 provides a 
number of very simple network simulation models:
  - an ipv4 and udp stack
  - arp support at the bottom of the stack
  - point-to-point physical-layer links
  - OnOff traffic generator

However, the framework is there to make adding new models as 
simple as possible:
  - an extensive tracing system can be used to connect
    any number of arbitrary trace sources to any number
    of trace sinks. This tracing system is decoupled
    from the act of serializing the trace events to a 
    file: users can and should provide their own
    trace handling routines.

  - simple file trace serialization support is included
    to both text and pcap files.

  - adding new MAC-level models simply requires subclassing
    the pair of classes NetDevice and Channel.

  - adding new traffic generation algorithms is also very 
    simple through the Application and the Socket classes.

3) Building ns-3
----------------

The code for the framework and the default models provided
by ns-3 is built as a set of libraries. User simulations
are expected to be written as simple programs which make
use of these ns-3 libraries.

To build the set of default libraries and the example
programs included in this package, you need to use the
tool 'scons'. Detailed information on how to install
and use scons is included in the file doc/build.txt

However, the real quick and dirty way to get started is to
type the command "scons" the the directory which contains
this README file. The files built will be copied in the
build-dir/dbg-shared/bin and build-dir/dbg-shared/lib
directories. build-dir/dbg-shared/bin will contain
one binary for each of the sample code in the 'samples'
directory and one binary for each of the detailed examples
found in the 'examples' directory.

The current codebase is expected to build and run on the
following set of platforms:
  - linux x86 gcc 4.1, gcc 3.4.
  - MacOS X ppc and x86

The current codebase is expected to fail to build on
the following platforms:
  - gcc 3.3 and earlier
  - optimized builds on linux x86 gcc 4.0 

Other platforms might or might not work: we welcome 
patches to improve the portability of the code to these
other platforms.

4) Running ns-3
---------------

On Recent Linux systems, once you have built ns-3, it 
should be easy to run the sample programs with the
following command:

./build-dir/dbg-shared/bin/simple-p2p

or:

cd build-dir/dbg-shared/bin
./simple-p2p

That program should generate a simple-p2p.tr text 
trace file and a set of simple-p2p-xx-xx.pcap binary
pcap trace files.

5) Working with the development version of ns-3
-----------------------------------------------

If you want to download and use the development version 
of ns-3, you need to use the tool 'mercurial'. A quick and
dirty cheat sheet is included in doc/mercurial.txt but
reading through the mercurial tutorials included on the
mercurial website is usually a good idea if you are not
familiar with it.

If you have successfully installed mercurial, you can get
a copy of the development version with the following
command:
"hg clone http://code.nsnam.org/ns-3-dev"