44.5 Example

The following is an example of using Tmix and Tmix_DelayBox. Another example can be found at tcl/ex/tmix/test-tmix.tcl. An example using one-way TCP instead of Full-TCP agents can be found at tcl/ex/tmix/test-tmix-oneway.tcl. The validation script test-suite-tmix.tcl is in tcl/test/ and can be run with the command test-all-tmix from that directory.

	# Simulation script to simulate the tmix-ns component

	#::::::::::: Useful Variables ::::::::::::::::::::::
	set end 3600;                       # length of traced simulation (s)
	set INBOUND "inbound.cvec"
	set OUTBOUND "outbound.cvec"

	#::::::::::: Setup Simulator ::::::::::::::::::::::
	remove-all-packet-headers;             # removes all packet headers
	add-packet-header IP TCP;              # adds TCP/IP headers
	set ns [new Simulator];                # instantiate the Simulator
	$ns use-scheduler Heap

	#::::::::::: Setup Topology ::::::::::::::::::::::
	# create nodes
	set n(0) [$ns node]
	set n(1) [$ns node]
	set n(2) [$ns node]
	set n(3) [$ns node]

	# create Tmix_DelayBox nodes
	set tmixNet(0) [$ns Tmix_DelayBox]
	$tmixNet(0) set-cvfile "$INBOUND" [$n(0) id] [$n(1) id]
	$tmixNet(0) set-lossless

	set tmixNet(1) [$ns Tmix_DelayBox]
	$tmixNet(1) set-cvfile "$OUTBOUND" [$n(3) id] [$n(2) id]
	$tmixNet(1) set-lossless

	# create links
	$ns duplex-link $n(0) $tmixNet(0) 1000Mb 0.1ms DropTail
	$ns duplex-link $n(2) $tmixNet(0) 1000Mb 0.1ms DropTail
	$ns duplex-link $tmixNet(0) $tmixNet(1) 1000Mb 0.1ms DropTail
	$ns duplex-link $tmixNet(1) $n(1) 1000Mb 0.1ms DropTail
	$ns duplex-link $tmixNet(1) $n(3) 1000Mb 0.1ms DropTail

	# set queue buffer sizes (in packets)  (default is 20 packets)
	$ns queue-limit $n(0) $tmixNet(0) 500
	$ns queue-limit $tmixNet(0) $n(0) 500
	$ns queue-limit $n(2) $tmixNet(0) 500
	$ns queue-limit $tmixNet(0) $n(2) 500
	$ns queue-limit $tmixNet(0) $tmixNet(1) 500
	$ns queue-limit $tmixNet(1) $tmixNet(0) 500
	$ns queue-limit $tmixNet(1) $n(1) 500
	$ns queue-limit $n(1) $tmixNet(1) 500
	$ns queue-limit $tmixNet(1) $n(3) 500
	$ns queue-limit $n(3) $tmixNet(1) 500
	
	#::::::::::: Setup TCP ::::::::::::::::::::::
	Agent/TCP/FullTcp set segsize_ 1460;           # set MSS to 1460 bytes
	Agent/TCP/FullTcp set nodelay_ true;           # disabling nagle
	Agent/TCP/FullTcp set segsperack_ 2;           # delayed ACKs
	Agent/TCP/FullTcp set interval_ 0.1;           # 100 ms

	#::::::::::: Setup Tmix ::::::::::::::::::::::
	set tmix(0) [new Tmix]
	$tmix(0) set-init $n(0);                 # name $n(0) as initiator
	$tmix(0) set-acc $n(1);                  # name $n(1) as acceptor
	$tmix(0) set-ID 7
	$tmix(0) set-cvfile "$INBOUND"

	set tmix(1) [new Tmix]
	$tmix(1) set-init $n(3);                 # name $n(3) as initiator
	$tmix(1) set-acc $n(2);                  # name $n(2) as acceptor
	$tmix(1) set-ID 8
	$tmix(1) set-cvfile "$OUTBOUND"

	#::::::::::: Setup Schedule ::::::::::::::::::::::
	$ns at 0.0 "$tmix(0) start"
	$ns at 0.0 "$tmix(1) start"
	$ns at $end "$tmix(0) stop"
	$ns at $end "$tmix(1) stop"
	$ns at [expr $end + 1] "$ns halt"

	$ns run