Otcl for NS2 (Acknowledgement Programe )

set  ns [new Simulator]
set  n1 [$ns node]
set  n2 [$ns node]

#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
}
$ns duplex-link $n1 $n2 5Mb 2ms DropTail


 #=== TCP connection setup starts here ===
set tcp [new Agent/TCP]
set sink [new Agent/TCPSink]
set ftp [new Application/FTP]
$ns attach-agent $n1 $tcp
$ns attach-agent $n2 $sink
$ftp attach-agent $tcp
$ns connect $tcp $sink
$ns at 0.0 "$ftp start"


$ns at 5.0 "finish"

#Run the simulation
$ns run

Otcl for Ns2 lecture 3

In this lecture we will add 4 nodes.
 ...Add following lines to your code done in lecture 1

#Define different colors for data flows

$ns color 1 Blue
$ns color 2 Red

#Create four nodes

set n0 [$ns node]
set n1 [$ns node]
set n2 [$ns node]
set n3 [$ns node]

#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 DropTail

$ns duplex-link-op $n0 $n2 orient right-down #set position of nodes
$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

#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

Tool Command Language - (Get data from user)

Getting input  from user.

Like in c programming language we use "scanf"  to obtain data from user like 

int x ;
printf("enter value of x \n");
scanf("%d", &x);

now in tcl we using following code to get data from user

puts "enter value of x "
set y [gets stdin] 
puts "$y"

Otcl for NS2 lecture 2

Transfer Data Between Two Nodes.

In the first tutorial we have created two nodes and now we will transfer data between them.

Add following lines to ist program

set udp0  [new Agent/UDP]  #we have created udp agent. An agent is an NsObject which is responsible for creating and destroying packets.
$ns attach-agent $n0 $udp0   #attach udp to node 0

set cbr0 [new Application/Traffic/CBR] #create a Constant Bit Rate source and attach it to udp0
$cbr0 set packetSize 500.. #packet size 500
$cbr0 set interval .005.. #after .005 sec next packet will b send
$cbr0 attach-agent $udp0

set null0 [new Agent/Null]
$ns attach-agent $n1 $null0 #node 1 will act now sinck

$ns connect $udp0 $null0 #connect source and sink

 $ns at .5 "$cbr0 start"
 $ns at 4.5 "$cbr0 stop "

OTCL for Ns2 Lecture 1

Create two nodes 
program:
     open any text editor and write below program 

set ns [new simulator]  #create a simulator obj [ see tcl first lect]
set nf [open out.name w ]  #open file out.nam assign nf to it . if file is not present it will create it.
$ns nametrace-all $nf #write all simulation data to this file.
           
proc  finish {} {
global ns nf
$ns flush-trace
close $nf
exec nam out.nam & 
exit 0
}
set n0 [ $ns new node]
set n1 [ $ns new node]
$ns duplex-link $n0 $n1 1Mb 10ms DropTail  #transfer rate 1Mb and delay 10ms
$ns at 5.0 "finish"
$ns run 

Now open terminal and go to place where u have saved the file and  write ns example.tcl 
out put: