Stop_and_wait_and_Sliding_window_protocol.tcl

set ns [new Simulator]

#puts "Starting program..."

# Creating Output files
set namf [open stop_wait_protocol.nam w]
$ns namtrace-all $namf

set trf [open stop_wait_protocol.tr w]
$ns trace-all $trf

# Finishing procedures
proc finish {} { 	
	global ns namf trf
	$ns flush-trace
	#puts "Saving namf and trf..."
	close $namf
	close $trf
	#puts "Opening Network animator..."
	exec nam stop_wait_protocol.nam &
	#puts "Closing program..."
	exit 0
}

# Creating nodes
set n0 [$ns node]
set n1 [$ns node]

# Setting links and setting queue size
$ns duplex-link $n0 $n1 0.2Mb 200ms DropTail
$ns duplex-link-op $n0 $n1 orient right
$ns queue-limit $n0 $n1 10

# Defining agents and setting src and dest 
set tcp [new Agent/TCP]
set sink [new Agent/TCPSink]
$ns attach-agent $n0 $tcp
$ns attach-agent $n1 $sink
$ns connect $tcp $sink

# Creating FTP 
set ftp [new Application/FTP]
$ftp attach-agent $tcp

# Stop and wait protocol
$tcp set window_ 1
$tcp set maxcwnd_ 1

# Use below 2 # for sliding window
#$tcp set windowInit_ 4
#$tcp set maxcwnd_ 4

# I dont know what these are.
$tcp set nam_tracevar_ true
$ns add-agent-trace $tcp tcp
$ns monitor-agent-trace $tcp
$tcp tracevar cwnd_

# Finishing and closing procedures
$ns at 0.1 "$ftp start"
$ns at 3.0 "$ns detach-agent $n0 $tcp"
$ns at 3.0 "$ns detach-agent $n1 $sink"
$ns at 3.5 "$ftp stop"
$ns at 5.0 "finish"
$ns run