1 / 13

ns-2 tutorial

ns-2 tutorial. CSCI 5931 Network Security Instructor : Dr. T. Andrew Yang . Karthik Sadasivam Banuprasad Samudrala. Introduction. Ns-2 is a discrete event simulator targeted at network research focused on modeling network protocols wired, wireless, satellite TCP, UDP, multicast, unicast

shepry
Download Presentation

ns-2 tutorial

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. ns-2 tutorial CSCI 5931 Network Security Instructor : Dr. T. Andrew Yang Karthik Sadasivam Banuprasad Samudrala

  2. Introduction • Ns-2 is a discrete event simulator targeted at network research • focused on modeling network protocols • wired, wireless, satellite • TCP, UDP, multicast, unicast • web, telnet, ftp • ad hoc routing, sensor networks • infrastructure: stats, tracing, error models, etc

  3. Goals of ns • support networking research and education • protocol design, traffic studies, etc. • protocol comparison • provide a collaborative environment • freely distributed, open source • share code, protocols, models, etc. • allow easy comparision of similar protocols • increase confidence in results • models provide useful results in several situations • multiple levels of detail in one simulator

  4. ns status • platforms: basically all Unix and Windows • size: about 200k loc each C++ and Tcl, 350 page manual • user-base: >1k institutions, >10k users • releases about every 6 months, plus daily snapshots

  5. Components of ns • ns, the simulator itself • nam, the Network AniMator • visualize ns (or other) output • GUI input simple ns scenarios • pre-processing: • traffic and topology generators • post-processing: • simple trace analysis, often in Awk, Perl, or Tcl

  6. ns Software Structure: C++ and Otcl • Uses two languages • C++ for packet-processing • fast to run, detailed, complete control • OTcl for control • simulation setup, configuration, occasional actions • fast to write and change • pros: trade-off running vs. writing speed, powerful/documented config language • cons: two languages to learn and debug in

  7. oTcl and C++: The Duality • OTcl (object variant of Tcl) and C++ share class hierarchy • TclCL is glue library that makes it easy to share functions, variables, etc. C++ otcl

  8. Installation and documentation • http://www.isi.edu/nsnam/ns/ • download ns-allinone • includes Tcl, OTcl, TclCL, ns, nam, etc. • mailing list: ns-users@isi.edu • documentation (see url above) • Marc Gries tutorial • ns manual

  9. Steps to set up the simulation • Initialize the simulator • Define files for output (tracing) • Set up the topology • Set up the “agents” • Set up the traffic between the nodes • Start the simulation • Analyze the trace files to compute the parameters of interest

  10. Example : TCP n0 n1 set ns [new Simulator] set n0 [$ns node] set n1 [$ns node] set ftp [new Application/FTP] $ftp attach-agent $tcp $ns at 0.2 "$ftp start" $ns at 1.2 ”exit" $ns run $ns duplex-link $n0 $n1 1.5Mb 10ms DropTail set tcp [new Agent/TCP] set tcpsink [new Agent/TCPSink] $ns attach-agent $n0 $tcp $ns attach-agent $n1 $tcpsink $ns connect $tcp $tcpsink

  11. Script to start nam set nf [open out.nam w] $ns namtrace-all $nf proc finish {} { global ns nf $ns flush-trace close $nf exec nam out.nam & exit 0 } # your code goes in here $ns at 12.0 "finish" # 12.0 is the simulation time in secs

  12. Screenshots Project B.2 Project B.1

  13. References [1] slides by John Heidemann http://sce.cl.uh.edu/yang/teaching/csci5931netSecuritySpr05/johnh_class_slides_sp2003.ppt [2] ns2 website: http://www.isi.edu/nsnam/ns [3] ns-2 Tutorial: http://www.isi.edu/nsnam/ns/tutorial/nsindex.html [4] Tcl/Tk tutorial : http://hegel.ittc.ukans.edu/topics/tcltk/tutorial-noplugin/

More Related