#Create Simulator object
set ns [new Simulator]
#Open trace file
set nt [open lab1.tr w]
$ns trace-all $nt
#Open namtrace file
set nf [open lab1.nam w]
$ns namtrace-all $nf
#Create nodes
set n0 [$ns node]
set n1 [$ns node]
set n2 [$ns node]
set n3 [$ns node]
#Assign color to the packet
$ns color 1 Blue
$ns color 2 Red
#label nodes
$n0 label "Source/udp0"
$n1 label "Source/udp1"
$n2 label "Router"
$n3 label "Destination/null"
#create links, specify the type, nodes, bandwidth, delay
and ARQ algorithm for it
$ns duplex-link $n0 $n2 10Mb 300ms DropTail
$ns duplex-link $n1 $n2 10Mb 300ms DropTail
$ns duplex-link $n2 $n3 100Kb 300ms DropTail
#set queue size between the nodes
$ns queue-limit $n0 $n2 10
$ns queue-limit $n1 $n2 10
$ns queue-limit $n2 $n3 5
#create and attach UDP agent to n0, n1 and Null agent to
n3
set udp0 [new Agent/UDP]
$ns attach-agent $n0 $udp0
set udp1 [new Agent/UDP]
$ns attach-agent $n1 $udp1
set null3 [new Agent/Null]
$ns attach-agent $n3 $null3
#attach Application cbr to udp
set cbr0 [new Application/Traffic/CBR]
$cbr0 attach-agent $udp0
set cbr1 [new Application/Traffic/CBR]
$cbr1 attach-agent $udp1
#set udp0 packet to red color and udp1 packet to blue
color
$udp0 set class_ 1
$udp1 set class_ 2
#connect the agents
$ns connect $udp0 $null3
$ns connect $udp1 $null3
#set packet size and interval for cbr1
$cbr1 set packetSize_ 500Mb
$cbr1 set interval_ 0.005
#finish procedure
proc finish { } {
global ns nf nt
$ns flush-trace
exec nam lab1.nam &
close $nt
close $nf
exit 0
}
$ns at 0.1 "$cbr0 start"
$ns at 0.1 "$cbr1 start"
$ns at 10.0 "finish"
$ns run
AWK file
BEGIN { count=0; }
{
if ($1=="d")
count++
}
END{
printf("Number of packets dropped is = %d\n", count);
}
Output:
[root@localhost 21cs52]# awk -f lab1.awk lab1.tr
Number of packets dropped is = 4065
#create Simulator object
set ns [new Simulator]
#open trace file
set nt [open Lab4.tr w]
$ns trace-all $nt
#open namtrace file
set nf [open Lab4.nam w]
$ns namtrace-all $nf
#create nodes
set n0 [$ns node]
set n1 [$ns node]
set n2 [$ns node]
set n3 [$ns node]
set n4 [$ns node]
set n5 [$ns node]
#label nodes
$n0 label "ping0"
$n1 label "ping1"
$n2 label "ping2"
$n3 label "ping3"
$n4 label "ping4"
$n5 label "router"
#create links, specify the type, nodes, bandwidth, delay
and ARQ algorithm for
it
$ns duplex-link $n0 $n5 1Mb 10ms DropTail
$ns duplex-link $n1 $n5 1Mb 10ms DropTail
$ns duplex-link $n2 $n5 1Mb 10ms DropTail
$ns duplex-link $n3 $n5 1Mb 10ms DropTail
$ns duplex-link $n4 $n5 1Mb 10ms DropTail
#set queue length
$ns queue-limit $n0 $n5 5
$ns queue-limit $n1 $n5 5
$ns queue-limit $n2 $n5 2
$ns queue-limit $n3 $n5 5
$ns queue-limit $n4 $n5 2
$ns color 2 Red
$ns color 3 Blue
$ns color 4 Green
$ns color 5 Yellow
#define ‘recv’ function for class Agent/Ping
Agent/Ping instproc recv {from rtt} {
$self instvar node_
puts "node [$node_ id] received ping answer from $from
with round-trip time $rtt
ms"
}
#create ping agent and attach them to node
set p0 [new Agent/Ping]
$ns attach-agent $n0 $p0
$p0 set class_ 1
set p1 [new Agent/Ping]
$ns attach-agent $n1 $p1
$p1 set class_ 2
set p2 [new Agent/Ping]
$ns attach-agent $n2 $p2
$p2 set class_ 3
set p3 [new Agent/Ping]
$ns attach-agent $n3 $p3
$p3 set class_ 4
set p4 [new Agent/Ping]
$ns attach-agent $n4 $p4
$p4 set class_ 5
#connect 2 agents
$ns connect $p2 $p4
$ns connect $p3 $p4
proc sendPingPacket { } {
global ns p2 p3
set intervalTime 0.001
set now [$ns now]
$ns at [expr $now + $intervalTime] "$p2 send"
$ns at [expr $now + $intervalTime] "$p3 send"
$ns at [expr $now + $intervalTime] "sendPingPacket"
}
proc finish { } {
global ns nt nf
$ns flush-trace
close $nt
close $nf
exec nam Lab4.nam &
exit 0
}
$ns at 0.1 "sendPingPacket"
$ns at 2.0 "finish"
$ns run
Awk file
BEGIN{
count=0;
}
{
if($1=="d")
count++
}
END{
printf ("Number of packets dropped is = %d\n",count);
}
import java.util.Scanner;
public class CRC
{
public static int n;
public static void main(String[] args)
{
// create scanner class object to take input from user
Scanner sc=new Scanner(System.in);
// To create an instance of a class, we u se the new keyword
followed by the constructor
of the class
CRC crc=new CRC();
String copy,rec,code,zero="0000000000000000";
System.out.println("enter the dataword to be sent");
code=sc.nextLine();
System.out.println("The dataword is "+code);
n=code.length();
System.out.println("Length of the dataword="+n);
copy=code;
code+=zero;
System.out.println("The modified codeword is"+code);
code=crc.divide(code);
copy=copy.substring(0,n)+code.substring(n);
System.out.print("CRC=");
System.out.println(code.substring(n));
System.out.println("transmitted frame is="+copy);
System.out.println("enter received data:");
rec=sc.nextLine();
if(zero.equals(crc.divide(rec).substring(n)))
System.out.println("correct bits received");
else
System.out.println("received frame contains one or more
error");
sc.close(); //Scanner is closed to release resources.
}
public String divide(String s)
{
String div="10001000000100001";
int i,j;
char x;
for(i=0;i<n;i++) // Outer loop for each bit of the dataword
{
x=s.charAt(i);
for(j=0;j<17;j++) // Inner loop for each bit of the CRC
polynomial
{
if(x=='1') //If the current bit of the dataword (x) is '1'
{
if(s.charAt(i+j)!=div.charAt(j)) //it checks if the
corresponding bits of the dataword and the
CRC polynomial are equal.
s=s.substring(0,i+j)+"1"+s.substring(i+j+1); //it performs
an XOR operation and
updates the string s
else
s=s.substring(0,i+j)+"0"+s.substring(i+j+1); // it performs
an XOR operation
}
}
}
return s;
}
}
import java.util.Scanner;
public class bucket {
public static void main(String[] args)
{
Scanner sc=new Scanner(System.in);
int bucket=0;
int op_rate,i,n,bsize;
System.out.println("Enter the number of packets");
n=sc.nextInt();
System.out.println("Enter the output rate of the bucket");
op_rate=sc.nextInt();
System.out.println("Enter the bucket size");
bsize=sc.nextInt();
System.out.println("Enter the arriving packets(size)");
int pkt[]=new int[n];
for(i=0;i<n;i++)
{
pkt[i]=sc.nextInt();
}
System.out.println("\nSec\tpsize\tBucket\tAccept/Reject\
tpkt_send");
System.out.println("----------------------------------------------------");
for(i=0;i<n;i++)
{
System.out.print(i+1+"\t"+pkt[i]+"\t");
if(bucket+pkt[i]<=bsize)
{
bucket+=pkt[i];
System.out.print(bucket+"\tAccept\t\
t"+min(bucket,op_rate)+"\n" +"");
bucket=sub(bucket,op_rate);
}
else
{
int reject=(bucket+pkt[i]-bsize);
bucket=bsize;
System.out.print(bucket+"\tReject "+reject+"\
t"+min(bucket,op_rate)+"\n");
bucket=sub(bucket,op_rate);
}
}
while(bucket!=0)
{
System.out.print((++i)+"\t0\t"+bucket+"\tAccept\t\
t"+min(bucket,op_rate)+"\t");
bucket=sub(bucket,op_rate);
}
}
static int min(int a,int b){
return ((a<b)?a:b);}
static int sub(int a,int b){
return (a-b)>0?(a-b):0;
}
}
Code-
#set ns Simulator
set ns [new Simulator]
#define color for data flow
$ns color 1 Blue
$ns color 2 Red
#open trace file
set tracefile1 [open lab6.tr w]
set winfile [open winfile w]
$ns trace-all $tracefile1
#open namtrace file
set namfile [open lab6.nam w]
$ns namtrace-all $namfile
#define finish procedure
proc finish { } {
global ns tracefile1 namfile
$ns flush-trace
close $tracefile1
close $namfile
exec nam lab6.nam &
exit 0
}
#create 6 nodes
set n0 [$ns node]
set n1 [$ns node]
set n2 [$ns node]
set n3 [$ns node]
set n4 [$ns node]
set n5 [$ns node]
$n1 shape box
#create link between nodes
$ns duplex-link $n0 $n2 2Mb 10ms DropTail
$ns duplex-link $n1 $n2 2Mb 10ms DropTail
$ns simplex-link $n2 $n3 0.3Mb 100ms DropTail
$ns simplex-link $n3 $n2 0.3Mb 100ms DropTail
#Nodes n(3) , n(4) and n(5) are considered in a LAN
set lan [$ns newLan "$n3 $n4 $n5" 0.5Mb 40ms LL
Queue/DropTail MAC/802_3]
#give node position(Orientation to the nodes)
$ns duplex-link-op $n0 $n2 orient right-down
$ns duplex-link-op $n1 $n2 orient right-up
$ns simplex-link-op $n3 $n2 orient left
$ns simplex-link-op $n2 $n3 orient right
#set queue size of link(n2-n3)(Setup queue b/w n(2)) and
n(3) and monitor the
queue)
$ns queue-limit $n2 $n3 20
#setup tcp connection
set tcp [new Agent/TCP]
$ns attach-agent $n0 $tcp
set sink [new Agent/TCPSink]
$ns attach-agent $n4 $sink
$ns connect $tcp $sink
$tcp set fid_ 1
$tcp set packetSize_ 552
#set ftp over tcp connection
set ftp [new Application/FTP]
$ftp attach-agent $tcp
#setup a TCP1 connection
set tcp1 [new Agent/TCP]
$ns attach-agent $n1 $tcp1
set sink1 [new Agent/TCPSink]
$ns attach-agent $n5 $sink1
$ns connect $tcp1 $sink1
$tcp1 set fid_ 2
$tcp1 set packetSize_ 552
set telnet0 [new Application/Telnet]
$telnet0 attach-agent $tcp1
#title congestion window1
set outfile1 [open congestion1.xg w]
puts $outfile1 "TitleText: Congestion Window-- Source _tcp"
puts $outfile1 "xUnitText: Simulation Time(Secs)"
puts $outfile1 "yUnitText: Congestion WindowSize"
#title congestion window2
set outfile2 [open congestion2.xg w]
puts $outfile2 "TitleText: Congestion Window-- Source
_tcp1"
puts $outfile2 "xUnitText: Simulation Time(Secs)"
puts $outfile2 "yUnitText: Congestion WindowSize"
proc plotWindow {tcpSource outfile} {
global ns
set time 0.1
set now [$ns now]
set cwnd [$tcpSource set cwnd_]
puts $outfile "$now $cwnd"
$ns at [expr $now+$time] "plotWindow $tcpSource
$outfile"
}
$ns at 0.1 "plotWindow $tcp $winfile"
$ns at 0.0 "plotWindow $tcp $outfile1"
$ns at 0.1 "plotWindow $tcp1 $outfile2"
$ns at 0.3 "$ftp start"
$ns at 0.5 "$telnet0 start"
$ns at 49.0 "$ftp stop"
$ns at 49.1 "$telnet0 stop"
$ns at 50.0 "finish"
$ns run
