The ns-3 Network Simulator Project

ns-3 is a packet-level network simulator for research and education.

ns-3 is a discrete-event, packet-level network simulator with an emphasis on networking research and education. Users of ns-3 can construct simulations of computer networks using models of traffic generators, protocols such as TCP/IP, and devices and channels such as Wi-Fi and LTE, and analyze/visualize the results. Simulation plays a vital role in the research and education process, because of the ability for simulations to obtain reproducible results (particularly for wireless protocol design), scale to large networks, and study systems that have not yet been implemented. A particular emphasis in ns-3 is the high degree of realism in the models and integration of the tool with VM environments and testbeds. Very large scale simulations are possible; simulations of millions of nodes have been published. ns-3 has been in development since 2005 and has been making regular releases since June 2008 (our last release was ns-3.30.1 in September 2019). The tool is in wide use; we have a users mailing list (Google Groups forum) of over 9000 members, roughly 700 posts per month. Our developers list has over 1500 subscribers, and the code base credits 220 authors, supported by roughly ten active maintainers. ns-3 is operated as an open source project, originally funded with financial backing from NSF grants and from the French government (and via help from GSoC, GCI and ESA SOCIS), but with most current contributions coming from interested researchers and students worldwide.

Primary Open Source License: GNU General Public License version 2.0 (GPL-2.0)

Programming Languages:

  • c
  • c++
  • python


  • network simulations
  • networking
  • research and development