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NETWORKS LAB-EXERCISE 4
Creating and simulating three different network topologies in Ns2 for 100 seconds,
measuring throughput and packet loss and plotting the result in graph.
1) Hybrid
Code:
set noOfNodes 10
set noOfNodes2 20
set ns [new Simulator]
set tr [open hybrid20.tr w ]
$ns trace-all $tr
set ftr [open out.nam w ]
$ns namtrace-all $ftr
proc finish { } {
global tr ftr ns
$ns flush-trace
close $tr
close $ftr
exec nam out.nam &
exit 0
}
for {set i 0} {$i < $noOfNodes2} {incr i} {
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set n($i) [ $ns node]
}
for {set i 1} {$i<$noOfNodes} {incr i} {
$ns duplex-link $n(0) $n($i) 1Mb 10ms DropTail
}
for {set i [expr $noOfNodes-1]} {$i<[expr $noOfNodes2-1]} {incr i} {
$ns duplex-link $n($i) $n([expr $i+1]) 1Mb 10ms DropTail
}
for {set i 0} {$i<$noOfNodes2} {incr i} {
if { $i % 2 == 0 } {
set tcp($i) [new Agent/TCP]
$ns attach-agent $n($i) $tcp($i)
} else {
set sink($i) [new Agent/TCPSink]
$ns attach-agent $n($i) $sink($i)
}
}
for {set i 1} {$i<$noOfNodes2} {incr i} {
if { $i % 2 != 0 } {
$ns connect $sink($i) $tcp([expr $i-1])
set ftp([expr $i-1]) [new Application/FTP]
$ftp([expr $i-1]) attach-agent $tcp([expr $i-1])
$ns at 0.$i "$ftp([expr $i-1]) start"
}
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$ns queue-limit $n(0) $n(1) 10
$ns queue-limit $n(0) $n(2) 10
$ns queue-limit $n(12) $n(13) 10
$ns queue-limit $n(16) $n(17) 10
# $ns queue-limit $n(22) $n(23) 10
$ns at 3.0 "finish"
$ns run
Graphs:
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===========================================================================
2) Line
Code:
set noOfNodes 25
set ns [new Simulator]
set tr [open line25.tr w ]
$ns trace-all $tr
set ftr [open out.nam w ]
$ns namtrace-all $ftr
proc finish { } {
global tr ftr ns
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$ns flush-trace
close $tr
close $ftr
exec nam out.nam &
exit 0
}
for {set i 0} {$i < $noOfNodes} {incr i} {
set n($i) [ $ns node ]
}
for {set i 0} {$i<[expr $noOfNodes-1]} {incr i} {
$ns duplex-link $n($i) $n([expr $i+1]) 1Mb 10ms DropTail
}
for {set i 0} {$i<$noOfNodes} {incr i} {
if { $i % 2 == 0 } {
set tcp($i) [new Agent/TCP]
$ns attach-agent $n($i) $tcp($i)
} else {
set sink($i) [new Agent/TCPSink]
$ns attach-agent $n($i) $sink($i)
}
}
for {set i 1} {$i<$noOfNodes} {incr i} {
if { $i % 2 != 0 } {
$ns connect $sink($i) $tcp([expr $i-1])
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set ftp([expr $i-1]) [new Application/FTP]
$ftp([expr $i-1]) attach-agent $tcp([expr $i-1])
$ns at 0.$i "$ftp([expr $i-1]) start"
}
}
$ns queue-limit $n(2) $n(3) 10
$ns queue-limit $n(6) $n(7) 10
$ns queue-limit $n(12) $n(13) 10
$ns queue-limit $n(16) $n(17) 10
$ns queue-limit $n(22) $n(23) 10
$ns connect $sink(1) $tcp(4)
$ns at 3.0 "finish"
$ns run
Graphs:
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========================================================================
3) Star
Code:
set noOfNodes 10
set ns [new Simulator]
set tr [open star10.tr w ]
$ns trace-all $tr
set ftr [open out.nam w ]
$ns namtrace-all $ftr
proc finish { } {
global tr ftr ns
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$ns flush-trace
close $tr
close $ftr
exec nam out.nam &
exit 0
}
for {set i 0} {$i < $noOfNodes} {incr i} {
set n($i) [ $ns node ]
}
for {set i 1} {$i<$noOfNodes} {incr i} {
$ns duplex-link $n(0) $n($i) 1Mb 10ms DropTail
}
for {set i 0} {$i<$noOfNodes} {incr i} {
if { $i % 2 == 0 } {
set tcp($i) [new Agent/TCP]
$ns attach-agent $n($i) $tcp($i)
} else {
set sink($i) [new Agent/TCPSink]
$ns attach-agent $n($i) $sink($i)
}
}
for {set i 1} {$i<$noOfNodes} {incr i} {
if { $i % 2 != 0 } {
$ns connect $sink($i) $tcp([expr $i-1])
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set ftp([expr $i-1]) [new Application/FTP]
$ftp([expr $i-1]) attach-agent $tcp([expr $i-1])
$ns at 0.$i "$ftp([expr $i-1]) start"
}
}
$ns queue-limit $n(2) $n(0) 3
$ns connect $sink(3) $tcp(2)
$ns queue-limit $n(6) $n(0) 3
$ns connect $sink(7) $tcp(6)
$ns at 3.0 "finish"
$ns run
Graphs
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