TWO TCP ONE UDP CONNECTION IN NS2....

#Create a simulator object
set ns [new Simulator]

#Define different colors for data flows (for NAM)
$ns color 1 Blue
$ns color 2 Red
$ns color 3 black


#Open the NAM trace file
set nf [open out.nam w]
$ns namtrace-all $nf

set ne [open out.tr w]
$ns trace-all $ne

#Define a 'finish' procedure
proc finish {} {
        global ns nf ne
        $ns flush-trace
        #Close the NAM trace file
        close $nf
     close $ne
        #Execute NAM on the trace file
        exec nam out.nam
        exec xgraph out.tr -geometry 1300x768 &
        exit 0
}

#Create four nodes
set a1 [$ns node]
set a2 [$ns node]
set a3 [$ns node]
set r1 [$ns node]
set r2 [$ns node]
set r3 [$ns node]
set r4 [$ns node]
set r5 [$ns node]
set r6 [$ns node]
set r7 [$ns node]
set r8 [$ns node]
set v [$ns node]


#Create links between the nodes
$ns duplex-link $a1 $r1 4Mb 1ms DropTail
$ns duplex-link $a2 $r2 2Mb 1ms DropTail
$ns duplex-link $a3 $r3 2Mb 2ms DropTail
$ns duplex-link $r1 $r4 4Mb 1ms DropTail
$ns duplex-link $r2 $r5 2Mb 1ms DropTail
$ns duplex-link $r3 $r6 2Mb 2ms DropTail
$ns duplex-link $r4 $r7 4Mb 1ms DropTail
$ns duplex-link $r5 $r7 2Mb 15ms DropTail
$ns duplex-link $r6 $r8 2Mb 20ms DropTail
$ns duplex-link $r7 $v 0.7Mb 10ms SFQ
$ns duplex-link $r8 $v 0.7Mb 15ms SFQ

# --------------LABELLING -----------------------------#

$ns at 0.0 "$a1 label a1"
$ns at 0.0 "$a2 label a2"
$ns at 0.0 "$a3 label a3"
$ns at 0.0 "$r1 label r1"
$ns at 0.0 "$r2 label r2"
$ns at 0.0 "$r3 label r3"
$ns at 0.0 "$r4 label r4"
$ns at 0.0 "$r5 label r5"
$ns at 0.0 "$r6 label r6"
$ns at 0.0 "$r7 label r7"
$ns at 0.0 "$r8 label r8"
$ns at 0.0 "$v label v"

#Set Queue Size of link (n2-n3) to 10
$ns queue-limit $r1 $r4 20
$ns queue-limit $r2 $r5 20
$ns queue-limit $r3 $r6 20
$ns queue-limit $r4 $r7 20
$ns queue-limit $r5 $r7 20
$ns queue-limit $r6 $r8 20
$ns queue-limit $v $r7 10
$ns queue-limit $v $r8 20

#Give node position (for NAM)
$ns duplex-link-op $v $r7 orient left-up
$ns duplex-link-op $v $r8 orient left-down
$ns duplex-link-op $r7 $r4 orient left-up
$ns duplex-link-op $r7 $r5 orient left-down
$ns duplex-link-op $r4 $r1 orient left
$ns duplex-link-op $r5 $r2 orient left
$ns duplex-link-op $r1 $a1 orient left-up
$ns duplex-link-op $r2 $a2 orient left
$ns duplex-link-op $r8 $r6 orient left-down
$ns duplex-link-op $r6 $r3 orient left
$ns duplex-link-op $r3 $a3 orient left

#Monitor the queue for link (n2-n3). (for NAM)
$ns duplex-link-op $r4 $r7 queuePos 0.5
$ns duplex-link-op $r5 $r7 queuePos 0.5
$ns duplex-link-op $r7 $v  queuePos 0.5
$ns duplex-link-op $r8 $v  queuePos 0.5


#Setup a TCP connection 1
set tcp [new Agent/TCP]
$tcp set class_ 2
$ns attach-agent $a1 $tcp
set sink [new Agent/TCPSink]
$ns attach-agent $v $sink
$ns connect $tcp $sink
$tcp set fid_ 1

#Setup a FTP over TCP connection
set ftp1 [new Application/FTP]
$ftp1 attach-agent $tcp
$ftp1 set type_ FTP

#Setup a TCP connection 1
set tcp [new Agent/TCP]
$tcp set class_ 2
$ns attach-agent $a2 $tcp
set sink [new Agent/TCPSink]
$ns attach-agent $v $sink
$ns connect $tcp $sink
$tcp set fid_ 2

#Setup a FTP over TCP connection
set ftp2 [new Application/FTP]
$ftp2 attach-agent $tcp
$ftp2 set type_ FTP


#Setup a UDP connection
set udp [new Agent/UDP]
$ns attach-agent $a3 $udp
set null [new Agent/Null]
$ns attach-agent $v $null
$ns connect $udp $null
$udp set fid_ 3

#Setup a CBR over UDP connection
set cbr [new Application/Traffic/CBR]
$cbr attach-agent $udp
$cbr set type_ CBR
$cbr set packet_size_ 1000
$cbr set rate_ 1mb
$cbr set random_ false


proc record {} {
        global sink0 sink1 sink2 f0 f1 f2
    #Get an instance of the simulator
    set ns [Simulator instance]
    #Set the time after which the procedure should be called again
        set time 0.5
    #How many bytes have been received by the traffic sinks?
        set bw0 [$sink0 set bytes_]
        set bw1 [$sink1 set bytes_]
        set bw2 [$sink2 set bytes_]
    #Get the current time
        set now [$ns now]
    #Calculate the bandwidth (in MBit/s) and write it to the files
        puts $f0 "$now [expr $bw0/$time*8/1000000]"
        puts $f1 "$now [expr $bw1/$time*8/1000000]"
        puts $f2 "$now [expr $bw2/$time*8/1000000]"
    #Reset the bytes_ values on the traffic sinks
        $sink0 set bytes_ 0
        $sink1 set bytes_ 0
        $sink2 set bytes_ 0
    #Re-schedule the procedure
        $ns at [expr $now+$time] "record"
}


#Schedule events for the CBR and FTP agents
$ns at 0.1 "$cbr start"
$ns at 1.0 "$ftp2 start"
$ns at 0.5 "$ftp1 start"
$ns at 4.0 "$ftp2 stop"
$ns at 4.0 "$ftp1 stop"
$ns at 4.5 "$cbr stop"

#Detach tcp and sink agents (not really necessary)
$ns at 4.5 "$ns detach-agent $a1 $tcp ; $ns detach-agent $v $sink"
$ns at 4.5 "$ns detach-agent $a2 $tcp ; $ns detach-agent $v $sink"

#Call the finish procedure after 5 seconds of simulation time
$ns at 5.0 "finish"

#Print CBR packet size and interval
puts "CBR packet size = [$cbr set packet_size_]"
puts "CBR interval = [$cbr set interval_]"

#Run the simulation
$ns run