Telnet and FTP for a wired network | NS2 Tutorial 4

TELNET and FTP for a Wired Network

In the above network, Node 0 to Node 5 is enabled with Telnet Application, and Node 4 to Node 1 is enabled with FTP Application. 

Both FTP and TElnet are application layer protocols use TCP as the transport Layer. 

Requisites:

OS: Ubuntu 22.04

NS Version: 2.35

Results: Throughput with the help of AWK script

Animation: NAM

Graphs: xgraph or gnuplot

PROGRAM

#===================================

#     Simulation parameters setup

#===================================

set val(stop)   10.5                     ;# time of simulation end

#===================================

#        Initialization        

#===================================

#Create a ns simulator

set ns [new Simulator]

#Open the NS trace file

set tracefile [open telnet.tr w]

$ns trace-all $tracefile

#Open the NAM trace file

set namfile [open telnet.nam w]

$ns namtrace-all $namfile

#===================================

#        Nodes Definition        

#===================================

#Create 6 nodes

set n0 [$ns node]

set n1 [$ns node]

set n2 [$ns node]

set n3 [$ns node]

set n4 [$ns node]

set n5 [$ns node]

#===================================

#        Links Definition        

#===================================

#Create links between nodes

$ns duplex-link $n0 $n2 100.0Mb 10ms RED

$ns queue-limit $n0 $n2 50

$ns duplex-link $n3 $n2 100.0Mb 10ms RED

$ns queue-limit $n3 $n2 50

$ns duplex-link $n1 $n2 100.0Mb 10ms RED

$ns queue-limit $n1 $n2 50

$ns duplex-link $n3 $n4 100.0Mb 10ms RED

$ns queue-limit $n3 $n4 50

$ns duplex-link $n3 $n5 100.0Mb 10ms RED

$ns queue-limit $n3 $n5 50

#Give node position (for NAM)

$ns duplex-link-op $n0 $n2 orient right-down

$ns duplex-link-op $n3 $n2 orient left

$ns duplex-link-op $n1 $n2 orient right-up

$ns duplex-link-op $n3 $n4 orient right-up

$ns duplex-link-op $n3 $n5 orient right-down

#===================================

#        Agents Definition        

#===================================

#Setup a TCP connection

set tcp0 [new Agent/TCP]

$ns attach-agent $n0 $tcp0

set sink3 [new Agent/TCPSink]

$ns attach-agent $n5 $sink3

$ns connect $tcp0 $sink3

$tcp0 set packetSize_ 1500

#Setup a TCP connection

set tcp1 [new Agent/TCP]

$ns attach-agent $n4 $tcp1

set sink2 [new Agent/TCPSink]

$ns attach-agent $n1 $sink2

$ns connect $tcp1 $sink2

$tcp1 set packetSize_ 1500

#===================================

#        Applications Definition        

#===================================

#Setup a TELNET Application over TCP connection

set telnet0 [new Application/Telnet]

$telnet0 attach-agent $tcp0

$ns at 1.0 "$telnet0 start"

$ns at 10.0 "$telnet0 stop"

$telnet0 set interval_ 0.002

$telnet0 set type_ Telnet

#Setup an FTP Application over a TCP connection

set ftp1 [new Application/FTP]

$ftp1 attach-agent $tcp1

$ns at 1.0 "$ftp1 start"

$ns at 10.0 "$ftp1 stop"

#===================================

#        Termination        

#===================================

#Define a 'finish' procedure

proc finish {} {

    global ns tracefile namfile

    $ns flush-trace

    close $tracefile

    close $namfile

    exec nam telnet.nam &

    exit 0

}

$ns at $val(stop) "$ns nam-end-wireless $val(stop)"

$ns at $val(stop) "finish"

$ns at $val(stop) "puts \"done\" ; $ns halt"

$ns run

When you run the above file using the command 

$ ns telnet.tcl 

The outputs generated are telnet.nam and telnet.tr 

The packet transmission is shown like this in the animation window below

Output NAM File

Nam output

Output Trace File

Trace

To get the throughput of the above file in bits per second, here is the awk script: 

Save the following code in a file called throughput.awk and store in the same place where the tcl code is also stored. 

BEGIN {

recv = 0

currTime = prevTime = 0

tic = 0.1

}

{

# Trace line format: normal

if ($2 != "-t") {

event = $1

time = $2

if (event == "+" || event == "-") node_id = $3

if (event == "r" || event == "d") node_id = $4

flow_id = $8

pkt_id = $12

pkt_size = $6

flow_t = $5

level = "AGT"

}

# Trace line format: new

if ($2 == "-t") {

event = $1

time = $3

node_id = $5

flow_id = $39

pkt_id = $41

pkt_size = $37

flow_t = $45

level = $19

}

# Init prevTime to the first packet recv time

if(prevTime == 0)

prevTime = time

# Calculate the total received packets' size

if (level == "AGT" &&  event == "r" ) {

# Store received packet's size

recv += pkt_size

# This 'if' is introduced to obtain clearer

# Plots from the output of this script

currTime += (time - prevTime)

if (currTime >= tic) {

printf("%15g %18g\n",time,(recv/currTime)*(8/1000))

recv = 0

currTime = 0

}

prevTime = time

}

}

END {

printf("\n\n")

}

The above file can be run using the command:

$ gawk -f throughput.awk out.tr

The above command will print the following which informs the throughput of using Telnet and FTP

AWK OUTPUT

 

The plotting of out.tr is looking like the following graph:

$ xgraph out.tr 

Xgraph

Gnuplot Output will be like this 

$ gnuplot 

gnuplot> plot "out.tr" using 1:2 with linespoints title "Throughput"

Gnuplot