# The topology replicates the one used by Nirav in his paper# no loss added  #set val(chan)           Channel/Sat                 ;#Channel Typeset val(netif)          Phy/Sat            ;# network interface typeset val(mac)            Mac/Sat                 ;# MAC typeset val(ifq)            Queue/DropTail  ;# interface queue type#set val(ifq)            Queue/XCPset val(ll)             LL/Sat                    ;# link layer typeset val(err)            MarkovErrorModel#set val(err)            ComplexMarkovErrorModel#set val(err)             UniformErrorProcset val(bw_up)          10Mbset val(bw_down)        10Mbset val(x)		250set val(y)		250#Experimrnting with shorted values#set durlistA     "11.2 0.25"set durlistA        "11.2 4.0"      ;# unblocked and blocked state duration avg valueset durlistB        "27.0 12.0 0.4 0.4"  ;# for complexmarkoverror model# set BW 10; # in Mb/s# set delay 254; # in ms# # Set the queue length (in packets)# set qlen [expr round([expr ($BW / 8.0) * $delay * 2])]; # set buffer to pipe size# puts "queue len = $qlen"# set val(ifqlen) $qlen# set sat link bandwidth and delayLL set bandwidth_ 10MbLL set delay_ 125msset val(bdp) [expr 10000 * 125]#LL/Sat/HDLC set window_size_ $val(bdp) # set selective repeat on; its GoBackN by default#LL/HDLC set selRepeat_ 1set qlen $val(bdp)puts "queue len = $qlen"set val(ifqlen) $qlenproc start_time {} {return 0; }# proc start_time {} {return [expr ([eval ns-random] / 2147483647.0) * 0.1]}proc UniformErrorProc {} {	global val	set	errObj [new ErrorModel]	$errObj unit bit	#$errObj FECstrength $val(FECstrength) 	#$errObj datapktsize 512	#$errObj cntrlpktsize 80	return $errObj}proc MarkovErrorModel {} {	global durlistA newrng_		puts [lindex $durlistA 0]	puts [lindex $durlistA 1]	#set errmodel [new ErrorModel/TwoStateMarkov $durlistA time]	set rv0 [new RandomVariable/Exponential]	set rv1 [new RandomVariable/Exponential]	$rv0 use-rng $newrng_	$rv1 use-rng $newrng_	$rv0 set avg_ [lindex $durlistA 0]	$rv1 set avg_ [lindex $durlistA 1]	set errmodel [new ErrorModel/TwoState $rv0 $rv1 time]	#$errmodel drop-target [new Agent/Null]	return $errmodel}proc ComplexMarkovErrorModel {} {	global durlistB newrng_	set errmodel [new ErrorModel/ComplexTwoStateMarkov $durlistB time $newrng_]		$errmodel drop-target [new Agent/Null] 	return $errmodel}proc stop {} {    global ns_ tracefd    $ns_ flush-trace    close $tracefd}proc setup {tcptype queuetype sources qlen duration file seed c_sources delay rate ecn} {	global val traces ns_ tracefd newrng_	# Initialize Global Variables	#ns-random $seed	set ns_		[new Simulator]	set newrng_ [new RNG]	$newrng_ seed $seed	set tracefd     [open no-arq.tr w]	$ns_ trace-all $tracefd	$ns_ eventtrace-all	$ns_ rtproto Static		# Create sat n(0)		# configure node, please note the change below.	$ns_ node-config -satNodeType geo \	    -llType $val(ll) \	    -ifqType $val(ifq) \	    -ifqLen $val(ifqlen) \	    -macType $val(mac) \	    -phyType $val(netif) \	    -channelType $val(chan) \	    -downlinkBW $val(bw_down) \	    -wiredRouting ON	set n(0) [$ns_ node]	$n(0) set-position -95	$ns_ node-config -satNodeType terminal	set n(100) [$ns_ node]	$n(100) set-position 37.9 -122.3; # Berkeley		set n(101) [$ns_ node]	$n(101) set-position 42.3 -71.1; # Boston	# Add GSLs to geo satellites	$n(100) add-gsl geo $val(ll) $val(ifq) $val(ifqlen) $val(mac) $val(bw_up) \	    $val(netif) [$n(0) set downlink_] [$n(0) set uplink_]		$n(101) add-gsl geo $val(ll) $val(ifq) $val(ifqlen) $val(mac) $val(bw_up) \	    $val(netif) [$n(0) set downlink_] [$n(0) set uplink_]		$n(101) interface-errormodel [$val(err)]		$ns_ unset satNodeType_		# create regular routers	set n(99) [$ns_ node]    ;#....node 3	set n(102) [$ns_ node]   ;#....node 4			# determine the actual queutype and save the one asked for     # assign queueing parameters -- simulate random drop with RED	if { [string match RandomDrop* $queuetype ] } then {		set queuetype [join \				   [concat "RED" \					[string range $queuetype [string length "RandomDrop"] end ]]\				   "" ]		Queue/$queuetype set thresh_ [expr 2* $qlen]		Queue/$queuetype set maxthresh_ [expr 2* $qlen]		# added for ECN comparison		Queue/$queuetype set setbit_ $ecn	} elseif { [string match RED* $queuetype ] } then {		#added by nirav		Queue/$queuetype set bytes_ false		Queue/$queuetype set queue_in_bytes_ false		# Queue/$queuetype set q_weight_ = -1		# Queue/$queuetype set max_p = 1		Queue/$queuetype set gentle_ true		#added by nirav		#Queue/$queuetype set thresh_ [expr $qlen * 0.5]		#Queue/$queuetype set maxthresh_ [expr $qlen * 0.75]		Queue/$queuetype set thresh_ 0		Queue/$queuetype set maxthresh_ 0		# added for ECN comparison		Queue/$queuetype set setbit_ $ecn	}			$ns_ duplex-link $n(99) $n(100) 10Mb 1ms $queuetype	$ns_ duplex-link $n(101) $n(102) 10Mb 1ms $queuetype		# Just to shut ns up about the uninitialized cwnd_frac_variable.	Agent/TCP set cwnd_frac_ 100;	# window needs to be big for long bw delays - it's a max value for cwnd_	# initially set at 20 packets.	#Agent/TCP/Reno set window_ 2000;	Agent/$tcptype set window_ $val(bdp)		# create nodes for sources and c_sources	puts "sources = $sources"	puts "c_sources = $c_sources"		for { set i 1 } {$i <= [expr 2* [expr $sources+$c_sources]]} {incr i} {	set n($i) [$ns_ node]	}		# connect sources and sinks to routers at 100 Mb/s	for {set i 1} {$i<=$sources} {incr i} {		$ns_ duplex-link $n($i) $n(99) 100Mb 1ms $queuetype		$ns_ duplex-link $n(102) $n([expr $i+$sources+$c_sources]) 100Mb 1ms $queuetype	}	# connect cross traffic sources and sinks	for {set i [expr $sources+1]} {$i<= [expr $c_sources+$sources]} {incr i} {		$ns_ duplex-link $n($i) $n(99) 10Mb 2ms $queuetype		$ns_ duplex-link $n(100) $n([expr $i+$sources+$c_sources]) 10Mb 2ms $queuetype	}	# Setup traffic flow between nodes	# Create source and sink Agents and connect them	for {set i 1} {$i<= [expr $sources+$c_sources]} {incr i} {	# Create the sender agent		set T($i) [new Agent/$tcptype]		# If Ecn is on set it in the sender		if { $ecn } { $T($i) set ecn_ 1 }		set hstcpflag 0		if {$hstcpflag==1} {			puts "creating high-speed connection"			set tcp($i) [$ns_ create-highspeed-connection TCP/Reno $n($i) TCPSink $n([expr $i+$c_sources+$sources]) $i]			if { $ecn } { $tcp($i) set ecn_ 1 }		} else {			puts "cerating normal $T($i) connection"			set tcp($i) [$ns_ create-connection $tcptype $n($i) TCPSink $n([expr $i+$c_sources+$sources]) $i]			if { $ecn } { $tcp($i) set ecn_ 1 }		}		if {$hstcpflag==1} {			[set tcp($i)] set windowOption_ 8			[set tcp($i)] set low_window_ 12.5			[set tcp($i)] set high_window_ 12500			[set tcp($i)] set high_p_ 0.0000096			[set tcp($i)] set high_decrease_ 0.1			puts "windowOption = [$tcp($i) set windowOption_]"			puts "low_window = [$tcp($i) set low_window_]"			puts "high_window = [$tcp($i) set high_window_]"			puts "high_p_ = [$tcp($i) set high_p_]"			puts "high_decrease = [$tcp($i) set high_decrease_]"		}		set F($i) [new Application/FTP]		$F($i) attach-agent $tcp($i)		$ns_ at [expr [start_time]+[expr ($i-1)*2]] "$F($i) start"	}	# tracing for sat links	$ns_ trace-all-satlinks $tracefd		# If TCP is in the $traces variable, ask the TCP aganets to trace their	# cwnd_ & seqno_ variable to a file of teh form $file.tcp_trace.source_number	if { [lsearch $traces "TCP"] != -1 } {		for {set i 1} {$i<= [expr $sources+$c_sources]} {incr i} {			$tcp($i) trace cwnd_			$tcp($i) trace t_seqno_			$tcp($i) attach [open "$file.tcp_trace.$i" "w"]		}	}		# set queue size to pipe size	$ns_ queue-limit $n(99) $n(100) $val(ifqlen)	$ns_ queue-limit $n(101) $n(102) $val(ifqlen)	# If $traces includes "queue" use the trace-quere facility to put the queue    # trace out into $file.queue1.  See the docs for the format.	if { [lsearch $traces "queue"] != -1 } {		$ns_ trace-queue $n(99) $n(100) [open "$file.queue1" "w"]	}	# setup routing	set satrouteobject_ [new SatRouteObject]	$satrouteobject_ compute_routes	# Stop the sim at $duration	puts "duration = $duration\n"	$ns_ at $duration "stop"	$ns_ at $duration "puts \"NS EXITING...\" ; $ns_ halt"		# start up.	puts "Starting Simulation..."	$ns_ run}	# traces are the set of info to be put outset traces [ list "TCP" "queue" ]# this boring code sets the given parameters from teh command line in order or# assigns defaults if they're not given.if { [llength $argv]>0} then { set sources [lindex $argv 0]}\else {set sources 1}if { [llength $argv]>1} then { set duration [lindex $argv 1]}\else {set duration 100}if { [llength $argv]>2} then { set file [lindex $argv 2]}\else {set file "no-arq"}if { [llength $argv]>3} then { set qlen [lindex $argv 3]}\else {set qlen 50 }if { [llength $argv]>4} then { set tcptype [lindex $argv 4]}\else {set tcptype "TCP/Reno"}if { [llength $argv]>5} then { set queuetype [lindex $argv 5]}\else {set queuetype "RED"}if { [llength $argv]>6} then { set seed [lindex $argv 6]}\else {set seed 0}if { [llength $argv]>7} then { set c_sources [lindex $argv 7]}\else {set  c_sources 0}if { [llength $argv]>8} then { set delay [lindex $argv 8]}\else {set delay "10ms"}if { [llength $argv]>9} then { set rate [lindex $argv 9]}\else {set rate "100k"}if { [llength $argv]>10} then { set ecn [lindex $argv 10]}\else {set ecn 1 }# Start the simputs "sources=$sources, duration=$duration, file=$file, qlen=$qlen, tcptype=$tcptype, queuetype=$queuetype, seec=$seed, c_sources=$c_sources"setup $tcptype $queuetype $sources $qlen $duration $file $seed $c_sources $delay $rate $ecn