PRE-REQUISITES:

Next we need to paste the below code to the Main.tcl file and save the file in the ns-2.35 folder.

Code:

set ns [new Simulator]

set tracefile [open out.tr w]

set namfile [open out.nam w]

$ns trace-all $tracefile

$ns namtrace-all $namfile

proc finish {} {

    global ns tracefile namfile

    $ns flush-trace

    close $tracefile

    close $namfile

    exec nam out.nam &

    exit 0

}

set n0 [$ns node]

set n1 [$ns node]

set n2 [$ns node]

set n3 [$ns node]

set n4 [$ns node]

$ns duplex-link $n0 $n1 1Mb 10ms DropTail

$ns duplex-link $n1 $n2 1Mb 10ms DropTail

$ns duplex-link $n2 $n3 1Mb 10ms DropTail

$ns duplex-link $n3 $n4 1Mb 10ms DropTail

# Set up TCP agent on node n0 (sender)

set tcp0 [new Agent/TCP]

$tcp0 set class_ TCP

$ns attach-agent $n0 $tcp0

# Set up TCP Sink on node n4 (receiver)

set sink [new Agent/TCPSink]

$ns attach-agent $n4 $sink

# Connect TCP source and sink

$ns connect $tcp0 $sink

# Create a TCP traffic generator and attach it to the TCP agent

set ftp [new Application/FTP]

$ftp attach-agent $tcp0

$ns at 0.5 “$ftp start”

$ns at 4.5 “$ftp stop”

$ns at 5.0 “finish”

$ns run

Screenshot: