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Program - 1
Question
Simulate a three nodes point – to – point network with duplex links between them.
Set the queue size and vary the bandwidth and find the number of packets dropped.
To execute:
To run the simulation:
$ns 1.tcl
To plot the graph:
$xgraph [-fg ][-bg ][-lw ] .xg
File: 1.tcl
#Create a new Simulation Instance
set ns [new Simulator]
#Turn on the Trace and the animation files
set f [open out.tr w]
set nf [open out.nam w]
$ns trace-all $f
$ns namtrace-all $nf
#Define the finish procedure to perform at the end of the simulation
proc finish {} {
global f nf ns
$ns flush-trace
close $f
close $nf
exec nam out.nam &
exec awk -f 1.awk out.tr &
exit 0
#Create the nodes
set n0 [$ns node]
set n1 [$ns node]
set n2 [$ns node]
#Label the nodes
$n0 label "TCP Source"
$n1 label "UDP Source"
$n2 label "Sink"
#Set the color
$ns color 1 red
$ns color 2 yellow
#Create the Topology
$ns duplex-link $n0 $n1 2Mb 10ms DropTail
$ns duplex-link $n1 $n2 1.75Mb 20ms DropTail
#Attach a Queue of size N Packets between the nodes n1 n
$ns queue-limit $n1 $n2 10
#Make the Link Orientation
$ns duplex-link-op $n0 $n1 orient right
$ns duplex-link-op $n1 $n2 orient right
#Create a UDP Agent and attach to the node n
set udp0 [new Agent/UDP]
$ns attach-agent $n0 $udp
#Create a CBR Traffic source and attach to the UDP Agent
set cbr0 [new Application/Traffic/CBR]
$cbr0 attach-agent $udp
#Specify the Packet Size and interval
$cbr0 set packetSize_ 500
$cbr0 set interval_ 0.
#Create a Null Agent and attach to the node n
set null0 [new Agent/Null]
$ns attach-agent $n2 $null
#Connect the CBR Traffic source to the Null agent
$ns connect $udp0 $null
#Create a TCP agent and attach to the node n
set tcp0 [new Agent/TCP]
$ns attach-agent $n0 $tcp
#Create a FTP source and attach to the TCP agent
set ftp0 [new Application/FTP]
File: 1.xg
TitleText: Performance Analysis (Bandwidth vs Packet Dropped)
XUnitText: Bandwidth(in Mbps)
YUnitText: No.of Packet Dropped
"CBR"
"TCP"
OUTPUT:
Program - 2
Question
Simulate a four node point-to-point network with the links connected as follows:
n0 – n2, n1 – n2 and n2 – n3. Apply TCP agent between n0-n3 and UDP between
n1-n3. Apply relevant applications over TCP and UDP agents changing the
parameter and determine the number of packets sent by TCP / UDP.
File: 2.tcl
set ns [new Simulator]
set f [open out.tr w]
set nf [open out.nam w]
$ns trace-all $f
$ns namtrace-all $nf
$ns color 1 "Blue"
$ns color 2 "Red"
proc finish {} {
global ns f nf
$ns flush-trace
close $f
close $nf
exec nam out.nam &
exec awk -f 2.awk out.tr &
exit 0
set n0 [$ns node]
set n1 [$ns node]
set n2 [$ns node]
set n3 [$ns node]
$ns duplex-link $n0 $n2 2Mb 10ms DropTail
$ns duplex-link $n1 $n2 2Mb 10ms DropTail
$ns duplex-link $n2 $n3 2.75Mb 20ms DropTail
$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
$ns queue-limit $n2 $n3 50
set udp0 [new Agent/UDP]
$ns attach-agent $n1 $udp
$udp0 set class_ 2
set cbr0 [new Application/Traffic/CBR]
$cbr0 attach-agent $udp
$cbr0 set packetSize_ 1000
$cbr0 set interval_ 0.
if((event=="d")&&(type=="cbr")) { CBRDrop++; } }
END {
printf "\nTCPSend %d", TCPSend; printf "\nCBRSend %d", CBRSend; printf "\nTCPDrop %d", TCPDrop; printf "\nCBRDrop %d", CBRDrop;
TCPArrivalRatio=((TCPSend-TCPDrop)/TCPSend); TCPDropRatio=(TCPDrop/TCPSend);
UDPArrivalRatio=((CBRSend-CBRDrop)/CBRSend); UDPDropRatio=(CBRDrop/CBRSend);
printf "\nTCPArrivalRatio %f", TCPArrivalRatio; printf "\nTCPDropRatio %f", TCPDropRatio; printf "\nUDPArrivalRatio %f", UDPArrivalRatio; printf "\nUDPDropRatio %f", UDPDropRatio; }
File: 2AR.xg
TitleText: Performance Analysis (Bandwidth vs Packet Arrival Ratio) XUnitText: Bandwidth(in Mbps) YUnitText: Packet arrival ratio
"TCP"
"CBR"
File: 2DR.xg
TitleText: Performance Analysis (Bandwidth vs Packet Arrival Ratio) XUnitText: Bandwidth(in Mbps) YUnitText: Packet arrival ratio
"TCP" 0.25 0. 0.50 0. 0.75 0. 1.0 0. 1.25 0. 1.5 0. 1.75 0. 2.0 0. 2.25 0. 2.5 0 2.75 0
"CBR"
Program - 3
Question
Simulate the transmission of ping messages over a network topology consisting of 6
nodes and find the number of packets dropped due to congestion.
File : 3.tcl
set ns [new Simulator] set f [open out.tr w] set nf [open out.nam w]
Agent/Ping instproc recv {from rtt} { global seq $self instvar node_ puts "The node [$node_ id] received an ACK from the node $from with RTT $rtt ms" }
$ping0 set class_ 1 $ping1 set class_ 2 $ping4 set class_ 4 $ping5 set class_ 5
$ns at 0.01 "sendPingPacket" $ns at 10.0 "finish" $ns run
File 3.xg
TitleText: Performance Analysis of Bandwidth v/s Packet Dropped xUnitText: Bandwidth in Mbps yUnitText: Packet Dropped
Program - 4
Question
Simulate an Ethernet LAN using n nodes (6-10), change error rate and
data rate and compare throughput.
File : 4.awk
#!/usr/bin/awk -f
BEGIN {
cbrPktReceived=0;
totalPktReceived=0;
ftpPktReceived=0;
throughput=0.0;
src=$3;
des=$4;
type=$5;
event=$1;
if((event=="+") && (src=="2") && (des=="6") && (type=="cbr"))
cbrPktReceived++;
if(($1=="+") && ($3=="2") && ($4=="6") && (type=="tcp"))
ftpPktReceived++;
totalPktReceived=cbrPktReceived+ftpPktReceived;
END {
throughput=((totalPktReceived5008)/(8*1000000));
printf "the throughput is:%f\n",throughput;
printf "the throughput is:%d\n",cbrPktReceived;
printf "the throughput is:%d\n",ftpPktReceived;
File : 4.xg
TitleText: Program 4
XUnitText: Error Rate
YUnitText: Throughput
$n0 label "TCP FTP Source" $n3 label "Sink Destination" $n5 label "TCP Telnet Source" $n7 label "Sink Destination"
#Create the LAN topology $ns make-lan "$n0 $n1 $n2 $n3 $n4 $n5 $n6 $n7" 10Mb 30ms LL Queue/DropTail Mac/802_
#Set up the TCP Agents set tcp1 [new Agent/TCP] $ns attach-agent $n0 $tcp set ftp1 [new Application/FTP] $ftp1 attach-agent $tcp set sink1 [new Agent/TCPSink] $ns attach-agent $n3 $sink $ns connect $tcp1 $sink $tcp1 set class_ 1
#Set up the telnet set tcp2 [new Agent/TCP] $ns attach-agent $n5 $tcp set telnet1 [new Application/FTP] $telnet1 attach-agent $tcp set sink2 [new Agent/TCPSink] $ns attach-agent $n7 $sink $ns connect $tcp2 $sink $telnet1 set type_ $sink $tcp2 set class_ 2
set outFile1 [open Congestion1.xg w] set outFile2 [open Congestion2.xg w]
puts $outFile1 "TitleText: Congestion Window Plot for TCP1" puts $outFile1 "XUnitText: SimulationTime(Secs)" puts $outFile1 "YUnitText: CongestionWindowSize" puts $outFile2 "TitleText: Congestion Window Plot for TCP2" puts $outFile2 "XUnitText: SimulationTime(Secs)" puts $outFile2 "YUnitText: CongestionWindowSize"
#define findWindowSize proc findWindowSize {tcpSource outFile} { global ns set now [$ns now] set cWindSize [$tcpSource set cwnd_] puts $outFile "$now $cWindSize" $ns at [expr $now + 0.1] "findWindowSize $tcpSource $outFile" }
#schedule the events $ns at 0.0 "findWindowSize $tcp1 $outFile1" $ns at 0.1 "findWindowSize $tcp2 $outFile2" $ns at 0.3 "$ftp1 start" $ns at 0.5 "$telnet1 start" $ns at 50.0 "$ftp1 stop" $ns at 50.0 "$telnet1 stop" $ns at 50.0 "finish" $ns run
File : Congestion1.xg
XUnitText: SimulationTime(Secs) YUnitText: CongestionWindowSize
- TitleText: Congestion Window Plot for TCP
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