Description:
This tcl script generates the two wired nodes n0 and n(1) .It uses the duplex link for node connection. Bandwidth between the nodes n(0) and n(1) is 1 Mbps and network delay is 10ms and it uses Drop tail queue. Here we create the SMTP traffic between the nodes n(0) and n(1) . In this script we connect the n(0) and n(1) with very high bandwidth . Here we start the communication from n(0) to n(1) at 0.2 second.
#Create a simulator object
set ns [new Simulator]
#Open a nam trace file
set nf [open out.nam w]
$ns namtrace-all $nf
#Define a 'finish' procedure
proc finish {} {
global ns nf
$ns flush-trace
close $nf
exec nam out.nam &
exit 0
}
set n0 [$ns node]
set n1 [$ns node]
$n0 color blue
$n1 color red
#Connect the nodes with two links
$ns duplex-link $n0 $n1 1Mb 10ms DropTail
proc smtp_traffic {node0 node1 } {
global ns
set smtp_UDP_agent [new Agent/UDP]
set smtp_UDP_sink [new Agent/UDP]
$ns attach-agent $node0 $smtp_UDP_agent
$ns attach-agent $node1 $smtp_UDP_sink
$ns connect $smtp_UDP_agent $smtp_UDP_sink
set smtp_UDP_source [new Application/Traffic/Exponential]
$smtp_UDP_source attach-agent $smtp_UDP_agent
$smtp_UDP_source set packetSize_ 210
$smtp_UDP_source set burst_time_ 50ms
$smtp_UDP_source set idle_time_ 50ms
$smtp_UDP_source set rate_ 100k
$ns at 0.2 "$smtp_UDP_source start"
$ns at 3.2 "$smtp_UDP_source stop"
}
smtp_traffic $n0 $n1
$ns at 4.0 "finish"
$ns run
Screen shows the packet movements form the node (0) to node (1).
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