ns (simulator)

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ns or the network simulator (also popularly called ns-2, in reference to its current generation) is a discrete event network simulator. It is popular in academia for its extensibility (due to its open source model) and plentiful online documentation. ns is popularly used in the simulation of routing and multicast protocols, among others, and is heavily used in ad-hoc research. ns supports an array of popular network protocols, offering simulation results for wired and wireless networks alike. It can be also used as limited-functionality network emulator.

ns is licensed for use under version 2 of the GNU General Public License.

Contents 1 Design 2 History 3 ns2 Architecture 4 Applications of ns 5 External links 6 References

[edit] Design

ns was built in C++ and provides a simulation interface through OTcl, an object-oriented dialect of Tcl. The user describes a network topology by writing OTcl scripts, and then the main ns program simulates that topology with specified parameters.

[edit] History

ns began development in 1989 as a variant of the REAL network simulator. By 1995, ns had gained support from DARPA, the VINT project at LBL, Xerox PARC, UCB, and USC/ISI.^[1]

ns is now developed in collaboration between a number of different researchers and institutions, including SAMAN (supported by DARPA), CONSER (through the NSF), and ICIR (formerly ACIRI). Long-running contributions have also come from Sun Microsystems and the UCB Daedelus and Carnegie Mellon Monarch projects, cited by the ns homepage for wireless code additions.

The latest version of ns-2 is 2.33. For documentation on recent changes, see the version 2 change log.

Generation 3 of ns has begun development as of July 1, 2006 and is projected to take four years.^[2]

[edit] ns2 Architecture

[edit] Applications of ns

• Topology Generation for large simulations
• Scenario generation in ns.
• NS Network Emulation Capability
• NS2 Visual Trace Analyzer (Test)

[edit] External links

• The Network Simulator - ns-2
• The official Nsnam Wiki
• ns-3 project
• A user created blog - for ns2 dummies
• a reference alternative for simulation of Wireless LAN with quality of service may be jemula802, an open-source event-driven simulation of 802.11 in JAVA.

[edit] References

1. ^ "The Network Simulator - ns-2." Information Sciences Institute. The University of Southern California. 13 July 2006 <http://www.isi.edu/nsnam/ns/>.
2. ^ "Ns-3." The Nsnam Wiki. 2 July 2006. Information Sciences Institute. <http://nsnam.isi.edu/nsnam/index.php/Ns-3>.