Preface
NS2 is an open-source event-driven simulator designed specifically for research
in computer communication networks. Since its inception in 1989, NS2 has
continuously gained tremendous interest from industry, academia, and govern-
ment. Having been under constant investigation and enhancement for years,
NS2 now contains modules for numerous network components such as routing,
transport layer protocol, application, etc. To investigate network performance,
researchers can simply use an easy-to-use scripting language to configure a net-
work, and observe results generated by NS2. Undoubtedly, NS2 has become
the most widely used open source network simulator, and one of the most
widely used network simulators.
Unfortunately, most research needs simulation modules which are beyond
the scope of the built-in NS2 modules. Incorporating these modules into NS2
requires profound understanding of NS2 architecture. Currently, most NS2
beginners rely on online tutorials. Most of the available information mainly
explains how to configure a network and collect results, but does not include
sufficient information for building additional modules in NS2. Despite its de-
tails about NS2 modules, the formal documentation of NS2 is mainly written
as a reference book, and does not provide much information for beginners. The
lack of guidelines for extending NS2 is perhaps the greatest obstacle, which
discourages numerous researchers from using NS2. At this moment, there is
no guide book which can help the beginners understand the architecture of
NS2 in depth.
The objective of this textbook is to act as a primer for NS2 beginners.
The book provides information required to install NS2, run simple examples,
modify the existing NS2 modules, and create as well as incorporate new mod-
ules into NS2. To this end, the details of several built-in NS2 modules are
explained in a comprehensive manner.
NS2 by itself contains numerous modules. As time elapses, researchers keep
developing new NS2 modules. This book does not include the details of all NS2
