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|
puts "sourcing ../../lan/vlan.tcl..."
source ../..//lan/vlan.tcl
source ../../lan/ns-mac.tcl
set opt(tr) out.tr
set opt(namtr) "MySnoop.nam"
set opt(seed) 0
set opt(stop) 10
set opt(node) 2
set opt(qsize) 100
set opt(bw) 10Mb
set opt(delay) 1ms
set opt(ll) LL
set opt(ifq) Queue/DropTail
set opt(mac) Mac/802_3
set opt(chan) Channel
set opt(tcp) TCP/Reno
set opt(sink) TCPSink
set opt(app) FTP
set loss_prob 10
proc finish {} {
global ns opt
$ns flush-trace
exec nam $opt(namtr) &
exit 0
}
proc create-trace {} {
global ns opt
if [file exists $opt(tr)] {
catch "exec rm -f $opt(tr) $opt(tr)-bw [glob $opt(tr).*]"
}
set trfd [open $opt(tr) w]
$ns trace-all $trfd
if {$opt(namtr) != ""} {
$ns namtrace-all [open $opt(namtr) w]
}
return $trfd
}
proc add-error {LossyLink} {
global loss_prob
# creating the uniform distribution random variable
set loss_random_variable [new RandomVariable/Uniform]
$loss_random_variable set min_ 0 # set the range of the random variable;
$loss_random_variable set max_ 100
# create the error model;
set loss_module [new ErrorModel]
$loss_module drop-target [new Agent/Null]
$loss_module set rate_ $loss_prob # set error rate to (0.1 = 10 / (100 - 0));
# error unit: packets (the default);
$loss_module unit pkt
# attach random var. to loss module;
$loss_module ranvar $loss_random_variable
# keep a handle to the loss module;
#set sessionhelper [$ns create-session $n0 $tcp0]
$LossyLink errormodule $loss_module
}
proc create-topology {} {
global ns opt
global lan node s d
set num $opt(node)
for {set i 1} {$i < $num} {incr i} {
set node($i) [$ns node]
lappend nodelist $node($i)
}
set lan [$ns make-lan $nodelist $opt(bw) \
$opt(delay) $opt(ll) $opt(ifq) $opt(mac) $opt(chan)]
set opt(ll) LL/LLSnoop
set opt(ifq) Queue/DropTail
$opt(ifq) set limit_ 100
# set up snoop agent
set node(0) [$ns node]
$lan addNode [list $node(0)] $opt(bw) $opt(delay) $opt(ll) $opt(ifq) $opt(mac)
# set source and connect to node(0)
set s [$ns node]
$ns duplex-link $s $node(0) 5Mb 20ms DropTail
$ns queue-limit $s $node(0) 100000
$ns duplex-link-op $s $node(0) orient right
# set dest and connect to node(1)
set d [$ns node]
$ns duplex-link $node(1) $d 5Mb 10ms DropTail
$ns queue-limit $node(1) $d 100000
$ns duplex-link-op $d $node(1) orient left
set LossyLink [$ns link $node(1) $d]
add-error $LossyLink
}
## MAIN ##
set ns [new Simulator]
set trfd [create-trace]
create-topology
#set tcp0 [$ns create-connection TCP/Reno $s TCPSink $node(1) 0]
#$tcp0 set window_ 30
#Create a infinite source agent (FTP) tcp and attach it to node n0
set tcp0 [new Agent/TCP/Reno]
$tcp0 set backoff_ 2
$tcp0 set window_ 30
$ns attach-agent $s $tcp0
set tcp_snk0 [new Agent/TCPSink]
$ns attach-agent $d $tcp_snk0
$ns connect $tcp0 $tcp_snk0
set ftp0 [$tcp0 attach-app FTP]
$ns at 0.0 "$ftp0 start"
$ns at $opt(stop) "finish"
$ns run
|
