Download - TNK092: Network Simulation - Nätverkssimulering

TNK092: Network Simulation - Nätverkssimulering

Lecture #1: Course basics and a first taste of NS2

Vangelis Angelakis Ph.D.

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

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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.

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[ aug. 28 ]

[ aug. 29 ]

[ aug. 31 ]

[ sept. 4 ]

[ sept. 5 ]

[ sept. 12 ]

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. 11th, you are expected to deliver a report on the lab assignment discussed in the session

of Sept. the 4th.

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[ sept. 4 ]

[ sept. 11 ]

[ oct. 2]

[oct. 16 ]

Lab Groups and Project Teams

For the Labs you MUST: Select a lab partner

DEADLINE:

TUESDAY, Sept. 4

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I M P O R T A N T

Project

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Implementation of (recent) research papers, with simulatory results

Available on the course webpage from Tuesday, Sept. 11th

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.

Project Deliverables

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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

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

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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

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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

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NS2

Hello World! (hello.tcl)

set ns [new Simulator]$ns at 1 “puts \“Hello World!\”” $ns at 1.5 “exit”$ns run

$ $ ns hello.tclHello World!$ |

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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


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 running13


if { expression } {<execute some commands>

} else {<execute some commands>

} The “if” command can be nested with other “if”s and with

“else”s that can appear in the ”<execute some commands>” part

To test for equality, we use == For inequality, we use !=

for {set i 0} {$i < 5} {incr i} {<execute some commands>

}

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proc blue { par1 par2 . . . } {global var1 var2<commands>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

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TCL basic #1

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TCL basic #2

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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/

http://wiki.tcl.tk/

Basic scripting: initialization & termination

1. Create a Simulator objectset ns [new Simulator]

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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

Definition of nodes & links

Create nodes

set n0 [$ns node]

set n1 [$ns node]

Link the nodesFormat follows: duplex-link $n0 $n1 <bandwidth> <propdelay> <queue_type>

e.g.:$ns duplex-link $n0 $n1 1Mb 10ms

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Definition of nodes & links: a simplex link

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An example

Create nodes

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Check: ns-default.tcl

Find there default value

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

}

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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

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n1

n0

tcp/udp

sink

Basic Scripts

Generating Traffic FTP

set ftp [new Application/FTP]

$ftp attach-agent $tcp

Telnet

set telnet [new Application/Telnet]

$telnet attach-agent $tcp

CBRset src [new Application/Traffic/CBR]

Exponential, or Pareto on-off

set src [new Application/Traffic/Exponential]

set src [new Application/Traffic/Pareto]

.........

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n1

n0

tcp

ftp

sink

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

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Basic Scripts

Schedule Events and Run Simulation Schedule Events

$ns at <time> <event>

<event>: 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

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Visualizing NAM

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Remember this:

Visualizing NAM

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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\””

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Visualizing NAM

Links Color

$ns duplex-link-op $n0 $n1 color "green”

Label$ns duplex-link-op $n0 $n1 label “backbone"

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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

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Example 1

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Example 1

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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

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#

#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

Visualizing NAM

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Example 3#Create a simulator objectset ns [new Simulator]

#Define different colors for data flows

$ns color 1 Blue$ns color 2 Red

#Open the nam trace fileset nf [open out.nam w]$ns namtrace-all $nf

#Define a 'finish' procedureproc 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 nodesset n0 [$ns node]set n1 [$ns node]set n2 [$ns node]set n3 [$ns node]

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#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 n0set udp0 [new Agent/UDP]$udp0 set class_ 1$ns attach-agent $n0 $udp0

# Create a CBR traffic source and attach it to udp0set cbr0 [new Application/Traffic/CBR]$cbr0 set packetSize_ 500$cbr0 set interval_ 0.005$cbr0 attach-agent $udp0

Example 3#Create a UDP agent and attach it to node n1set udp1 [new Agent/UDP]$udp1 set class_ 2$ns attach-agent $n1 $udp1


#Create a Null agent (a traffic sink) and attach it to node n3set 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

Example 4

#Create a simulator objectset ns [new Simulator]

#Tell the simulator to use dynamic routing$ns rtproto DV

#Open the nam trace fileset nf [open out.nam w]$ns namtrace-all $nf

#Define a 'finish' procedureproc 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 nodesfor {set i 0} {$i < 7} {incr i} { set n($i) [$ns node]}

#Create links between the nodesfor {set i 0} {$i < 7} {incr i} { $ns duplex-link $n($i) $n([expr ($i+1)%7]) 1Mb 10ms DropTail}

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#Create links between the nodesfor {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 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

Download - TNK092: Network Simulation - Nätverkssimulering

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