# Lab1 C
# Set up below network topology. 
#
#     0
#      \
#       \
#        2------3
#       /
#      /
#     1
#
# create event scheduler
set ns [new Simulator]

# setup color mapping
$ns color 0 blue
$ns color 1 red

# create nodes
set n0 [$ns node]
#
# fill in code here...
#

# enable tracing
set f [open out.tr w]
$ns trace-all $f
set nf [open out.nam w]
$ns namtrace-all $nf

$ns duplex-link $n0 $n2 5Mb 2ms DropTail
$ns duplex-link $n1 $n2 5Mb 2ms DropTail
#
# fill in code here...
#

# topology layout
$ns duplex-link-op $n0 $n2 orient right-up
$ns duplex-link-op $n1 $n2 orient right-down
$ns duplex-link-op $n2 $n3 orient right
$ns duplex-link-op $n2 $n3 queuePos 0.5

# enable variable tracing for TCP
Agent/TCP set nam_tracevar_ true

# create TCP traffic 
set tcp [new Agent/TCP]
#set tcp [new Agent/TCP/Reno]
#set tcp [new Agent/TCP/Newreno]
$tcp set class_ 0
set sink [new Agent/TCPSink]
#
# fill in here
#
# Equivelant of 
# set tcp [$ns create-connection TCP $n0 TCPSink $n3 0]

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

#setup UDP
set udp [new Agent/UDP]
$udp set class_ 1
$ns attach-agent $n1 $udp
set null [new Agent/Null]
$ns attach-agent $n3 $null
#
# fill in here
#

# add CBR traffic
set cbr [new Application/Traffic/CBR]
#
# fill in here
#
$cbr attach-agent $udp

#start and stop traffic
#
# fill in code here 
#

$ns at 2.0 "finish"

proc finish {} {
    global ns f nf
    $ns flush-trace
    close $f
    close $nf
    
    # nam graph tracing filtering
    puts "Filtering ..."
    exec tclsh ../sample/namfilter.tcl out.nam
    
    # run animation
    puts "running nam..."
    exec nam out.nam &
    exit 0
}

$ns run