1. TNK092: Network Simulation - Nätverkssimulering Lecture #1: Course basics and a first taste of NS2 Vangelis Angelakis Ph.D.

2. Basic Course Information Examiner: Prof. Di Yuan Seminars: Dr. Vangelis Angelakis Labs: Ms. Qing He 6 ECTS, Load distribution:  Lab assignments: 2/6  Project work: 4/6 Subscribe to the course mailing list!! Webpage at: www.itn.liu.se/~vanan11/TNK092 2

3. Lectures 1.Course basics and first NS2 steps. 2.Manipulating results and adding modules 3.TCP/IP in NS2 4.Routing and network Dynamics 5.Wireless Networking Simulation 6.Wired & Wireless [sept. 21] backup lecture date. 3 [ aug. 28 ] [ aug. 29 ] [ aug. 31 ] [ sept. 4 ] [ sept. 5 ] [ sept. 12 ]

4. Assignments & Lab sessions 1.Learning to handle NS2 2.Setting up a new module in NS2 3.TCP/IP 4.Wireless networking 4 (+1) Lab sessions: Give you assistance on given assignment The 2 first give you hints & the basic steps on  how to proceed with it  what to expect The 2 last expect you to have done most of the job by then  assistive role. At the end of a lab session you DELIVER the report on the previous lab assignment  i.e.: on the session of Tue. Sept. 11 th, you are expected to deliver a report on the lab assignment discussed in the session of Sept. the 4 th. 4 [ sept. 4 ] [ sept. 11 ] [ oct. 2] [oct. 16 ]

5. Lab Groups and Project Teams For the Labs you MUST:  Select a lab partner  DEADLINE: TUESDAY, Sept. 4 5 I M P O R T A N T

6. Project 6 Implementation of (recent) research papers, with simulatory results Available on the course webpage from Tuesday, Sept. 11 th By Tuesday SEP. 18 23:59 email the course list (+ me) stating:  The names of TWO (2) students forming a project group  A list of 2-3 papers that the group is interested in IN ORDER OF PREFERENCE  Assignment of papers will be done in a first-come-first served manner, BUT:  Some groups may be assigned the same paper Such groups MUST work separately Reports and codes of these groups will be compared to identify integrity issues.

7. Project Deliverables 7 1.Project PROPOSAL By TUESDAY SEP. 30: NO extensions a brief summary identifying the paper’s KEY IDEA and the MAIN RESULT a list of the key points to implement that will illustrate them a list of the key system parameters, as the ones contained in the paper along with potential added assumptions 2.FINAL Report By SUNDAY OCT. 21: NO extensions  NS2 Implementation  Written 5-page (double-column) report  If FAIL deadlines for project resubmission (retake): Jan. 20, 2013 Aug. 25, 2013 -Details on the course website

8. Other timeslots 1.lab time exceeding the assignments: One extra session [ Oct. 16] 2.Project tutorial sessions on a project group need-to-do basis i.e. BY EMAIL APPOINTMENT! Sept 21: 8:15-10:15 Oct. 3: 17:15-19:15 Oct. 9: 13:15-17:15 Further tutorial may be arranged (upon availability only) by further email arrangements 8

9. Some resources NS simulator for beginners: http://www-sop.inria.fr/members/Eitan.Altman/ns.htm http://www-sop.inria.fr/members/Eitan.Altman/COURS-NS/n3.pdf NS by example: http://nile.wpi.edu/NS/ The ns-2 wiki, user information: http://nsnam.isi.edu/nsnam/index.php/User_Information Getting started with ns-2: http://nsnam.isi.edu/nsnam/index.php/Getting_Started_with_NS-2 9

10. Installation For Linux (Redhat, Ubuntu), FreeBSD, or other,  gcc needed  download ns-allinone software package, unzip (tar)  building ns from the sources (./install)  remember the enviromental variables (.bashrc in your own directory) For Windows  using Vmware Player (Free) will be the one used later on for the Lab download the ubuntu image for vmware, and install ns on your linux system: DETAILED INSTRUCTIONS ON THE COURSE WEB-PAGE  using Cygwin (Free) install Cygwin (www.cygwin.com), install all the packages if you don’t know which one you need instead of the defaut one download nsallinonesoftware package, unzip (tar) to one directory build ns source (./install) remember the enviromental variable (.bashrc) See Lab instructions or NS2 homepage for detailed information 10

11. NS2 Hello World! (hello.tcl) set ns [new Simulator] $ns at 1 “puts \“Hello World!\”” $ns at 1.5 “exit” $ns run $ $ ns hello.tcl Hello World! $ | 11

12. Tcl programming fundamentals 1/4 # This is a comment,the tcl interpreter will not “see” it set b 0 assigns to b the value 0 set x $a assigns to variable ‘ x ’ the value of variable ‘ a ’  To use the value assigned to a variable, we use the $ sign before the variable. set x [expr $a + $b]  A mathematical operation is done using the expr (ession) command. set myFilePtr [open my_filename w] opens my_filename for writing and gives you the pointer myFilePtr 12

13. Tcl programming fundamentals 2/4 puts $myFilePtr "text"  each time the puts command is used, a new line is started.  To avoid new line, one has to add -nonewline after puts  Tabulating is done by inserting \t puts "[expr 1/60]" will print ‘0’ on the screen  In Tcl the variables have no specific type, so a variable can be a string or an integer depending on the value you assign to it. puts "[expr 1.0/60.0]" to get the correct result exec xgraph data & Executes the unix program xgraph with input the file data. the & is used for background running 13

14. Tcl programming fundamentals 3/4 if { expression } { } else { }  The “ if ” command can be nested with other “ if ”s and with “ else ”s that can appear in the ” ” part  To test for equality, we use ==  For inequality, we use != for {set i 0} {$i < 5} {incr i} { } 14

15. Tcl programming fundamentals 4/4 proc blue { par1 par2... } { global var1 var2 return $something } This procedure is called by typing: blue x y in our tcl script  The values of x and y will be used by the procedure for par1 and par2. If par1 and par2 are changed within the procedure, this will not affect the values of x and y at the caller level (…“by value” argument passing)  On the other hand, if we wish the procedure to be able to affect directly variables external to it, we have to declare these variables as " global ". In the above example these are var1 and var2 15

16. TCL basic #1 16

17. TCL basic #2 17 fmod : Return the remainder after dividing expression x by expression y. break : could be used here... Notice there is a TCL commands wiki at: http://wiki.tcl.tk/

18. Basic scripting: initialization & termination 1. Create a Simulator object set ns [new Simulator] 18 3. The finish procedure: Flushing & closing the traces proc finish{} { global ns trc_file nam_file $ns flush-trace close trc_file close nam_file exec nam out.nam & exit 0 } 2. Output Traces: set file1 [open out.tr w] $ns trace-all $trc_file Data trace for all links set file2 [open out.nam w] $ns nametrace-all $nam_file Visual trace using the nam file format

19. Definition of nodes & links Create nodes set n0 [$ns node] set n1 [$ns node] Link the nodes Format follows: duplex-link $n0 $n1 e.g.: $ns duplex-link $n0 $n1 1Mb 10ms 19

20. Definition of nodes & links: a simplex link 20

21. An example Create nodes 21 Check: ns-default.tcl Find there default value

22. Basic networking scripts An ”automated” topology example for {set i 0} {$i < 7} {incr i} { set n($i) [$ns node] } for {set i 0} {$i < 7} {incr i} { $ns duplex-link $n($i) $n([expr($i+1)%7]) 1Mb 10ms RED } 22

23. Agents and applications Creating Data Connections  TCP set tcp [new Agent/TCP] set tcpsink [new Agent/TCPSink] $ns attach-agent $n0 $tcp $ns attach-agent $n1 $tcpsink $ns connect $tcp $tcpsink  UDP set udp [new Agent/UDP] set null [new Agent/NULL] $ns attach-agent $n0 $udp $ns attach-agent $n1 $null $ns connect $udp $null 23 n1 n0 tcp/udp sink

24. Basic Scripts Generating Traffic  FTP set ftp [new Application/FTP] $ftp attach-agent $tcp  Telnet set telnet [new Application/Telnet] $telnet attach-agent $tcp  CBR set src [new Application/Traffic/CBR]  Exponential, or Pareto on-off set src [new Application/Traffic/Exponential] set src [new Application/Traffic/Pareto]......... 24 n1 n0 tcp ftp sink

25. Basic Scripts Insert Link dynamics Creating Error Module set loss_module[new ErrorModel] $loss_moduleset rate_ 0.01 $loss_moduleunit pkt $loss_module ranvar[new RandomVariable/Uniform] $loss_moduledrop-target [new Agent/Null] Inserting an Error Module $ns lossmodel $loss_module$n0 $n1 25

26. Basic Scripts Schedule Events and Run Simulation  Schedule Events $ns at  : any legitimate ns/tcl command $ns at 0.5 “$cbr start” $ns at 4.5 “$cbr stop”  Call ‘finish’ $ns at 5.0 “finish”  Run the simulation $ns run 26

27. Visualizing NAM 27 Remember this:

28. Visualizing NAM 28

29. Visualizing NAM Nodes  Color $node color red  Shape (can’t be changed after simulation starts) $node shape box (circle, box, hexagon)  Label (single string) $ns at 1.1 “$n0 label \”web cache 0\”” 29

30. Visualizing NAM Links  Color $ns duplex-link-op $n0 $n1 color "green”  Label $ns duplex-link-op $n0 $n1 label “backbone" 30

31. Visualizing NAM Layout  “Manual” layout: specify everything $ns duplex-link-op $n(0) $n(1) orient right $ns duplex-link-op $n(1) $n(2) orient right $ns duplex-link-op $n(2) $n(3) orient right $ns duplex-link-op $n(3) $n(4) orient 60deg  If anything missing  automatic layout 31

32. Example 1 32

33. Example 1 33

34. Example 2 #Create a simulator object set ns [new Simulator] #Open the nam trace file set nf [open out.nam w] $ns namtrace-all $nf #Define a 'finish' procedure proc finish {} { global ns nf $ns flush-trace #Close the trace file close $nf #Execute nam on the trace file exec nam out.nam & exit 0 } #Create two nodes set n0 [$ns node] set n1 [$ns node] #Create a duplex link between the nodes $ns duplex-link $n0 $n1 1Mb 10ms DropTail 34 # #Create a UDP agent and attach it to node n0 set udp0 [new Agent/UDP] $ns attach-agent $n0 $udp0 # Create a CBR traffic source and attach it to udp0 set cbr0 [new Application/Traffic/CBR] $cbr0 set packetSize_ 500 $cbr0 set interval_ 0.005 $cbr0 attach-agent $udp0 #Create a Null agent (a traffic sink) and attach it to node n1 set null0 [new Agent/Null] $ns attach-agent $n1 $null0 #Connect the traffic source with the traffic sink $ns connect $udp0 $null0 #Schedule events for the CBR agent $ns at 0.5 "$cbr0 start" $ns at 4.5 "$cbr0 stop" #Call the finish procedure after 5 seconds of simulation time $ns at 5.0 "finish" #Run the simulation $ns run

35. Visualizing NAM 35

36. Example 3 #Create a simulator object set ns [new Simulator] #Define different colors for data flows $ns color 1 Blue $ns color 2 Red #Open the nam trace file set nf [open out.nam w] $ns namtrace-all $nf #Define a 'finish' procedure proc finish {} { global ns nf $ns flush-trace #Close the trace file close $nf #Execute nam on the trace file exec nam out.nam & exit 0 } #Create four nodes set n0 [$ns node] set n1 [$ns node] set n2 [$ns node] set n3 [$ns node] 36 #Create links between the nodes $ns duplex-link $n0 $n2 1Mb 10ms DropTail $ns duplex-link $n1 $n2 1Mb 10ms DropTail $ns duplex-link $n3 $n2 1Mb 10ms SFQ $ns duplex-link-op $n0 $n2 orient right-down $ns duplex-link-op $n1 $n2 orient right-up $ns duplex-link-op $n2 $n3 orient right #Monitor the queue for the link between node 2 and node 3 $ns duplex-link-op $n2 $n3 queuePos 0.5 #Create a UDP agent and attach it to node n0 set udp0 [new Agent/UDP] $udp0 set class_ 1 $ns attach-agent $n0 $udp0 # Create a CBR traffic source and attach it to udp0 set cbr0 [new Application/Traffic/CBR] $cbr0 set packetSize_ 500 $cbr0 set interval_ 0.005 $cbr0 attach-agent $udp0

37. Example 3 #Create a UDP agent and attach it to node n1 set udp1 [new Agent/UDP] $udp1 set class_ 2 $ns attach-agent $n1 $udp1 # Create a CBR traffic source and attach it to udp1 set cbr1 [new Application/Traffic/CBR] $cbr1 set packetSize_ 500 $cbr1 set interval_ 0.005 $cbr1 attach-agent $udp1 #Create a Null agent (a traffic sink) and attach it to node n3 set null0 [new Agent/Null] $ns attach-agent $n3 $null0 #Connect the traffic sources with the traffic sink $ns connect $udp0 $null0 $ns connect $udp1 $null0 #Schedule events for the CBR agents $ns at 0.5 "$cbr0 start" $ns at 1.0 "$cbr1 start" $ns at 4.0 "$cbr1 stop" $ns at 4.5 "$cbr0 stop" #Call the finish procedure after 5 seconds of simulation time $ns at 5.0 "finish" #Run the simulation $ns run 37

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39. Example 4 #Create a simulator object set ns [new Simulator] #Tell the simulator to use dynamic routing $ns rtproto DV #Open the nam trace file set nf [open out.nam w] $ns namtrace-all $nf #Define a 'finish' procedure proc finish {} { global ns nf $ns flush-trace #Close the trace file close $nf #Execute nam on the trace file exec nam out.nam & exit 0 } #Create seven nodes for {set i 0} {$i < 7} {incr i} { set n($i) [$ns node] } #Create links between the nodes for {set i 0} {$i < 7} {incr i} { $ns duplex-link $n($i) $n([expr ($i+1)%7]) 1Mb 10ms DropTail } 39 #Create links between the nodes for {set i 0} {$i < 7} {incr i} { $ns duplex-link $n($i) $n([expr($i+1)%7]) 1Mb 10ms DropTail } #Create a UDP agent and attach it to node n(0) set udp0 [new Agent/UDP] $ns attach-agent $n(0) $udp0 # Create a CBR traffic source and attach it to udp0 set cbr0 [new Application/Traffic/CBR] $cbr0 set packetSize_ 500 $cbr0 set interval_ 0.005 $cbr0 attach-agent $udp0 #Create a Null agent (a traffic sink) #and attach it to node n(3) set null0 [new Agent/Null] $ns attach-agent $n(3) $null0 #Connect the traffic source with the traffic sink $ns connect $udp0 $null0 #Schedule events for the CBR agent # and the network dynamics $ns at 0.5 "$cbr0 start" $ns rtmodel-at 1.0 down $n(1) $n(2) $ns rtmodel-at 2.0 up $n(1) $n(2) $ns at 4.5 "$cbr0 stop" #Call the finish procedure after 5 seconds #of simulation time $ns at 5.0 "finish" #Run the simulation $ns run

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