1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
#
# A simple (but not too realistic) rate-based congestion control
# scheme for Homework 3 in CS268.
#
# $Header: /cvsroot/nsnam/ns-2/tcl/ex/rc.tcl,v 1.4 1998/09/01 17:01:19 tomh Exp $
#
source timer.tcl
set ns [new Simulator]
proc build_topology { ns which } {
$ns color 1 red
$ns color 2 white
foreach i "0 1 2 3" {
global n$i
set tmp [$ns node]
set n$i $tmp
}
$ns duplex-link $n0 $n2 5Mb 2ms DropTail
$ns duplex-link $n1 $n2 5Mb 2ms DropTail
$ns duplex-link-op $n0 $n2 orient right-down
$ns duplex-link-op $n1 $n2 orient right-up
if { $which == "FIFO" } {
$ns duplex-link $n2 $n3 1.5Mb 10ms DropTail
} elseif { $which == "RED" } {
$ns duplex-link $n2 $n3 1.5Mb 10ms RED
} else {
$ns duplex-link $n2 $n3 1.5Mb 10ms FQ
}
$ns duplex-link-op $n2 $n3 orient right
$ns duplex-link-op $n2 $n3 queuePos 0.5
}
Class Agent/Message/Sender -superclass {Agent/Message Timer}
Class Agent/Message/Receiver -superclass Agent/Message
Agent/Message/Sender instproc init {} {
$self next
$self instvar cbr_ seq_ udp_
set udp_ [new Agent/UDP]
set cbr_ [new Application/Traffic/CBR]
$cbr_ attach-agent $udp_
set seq_ 1
$self sched [$self randomize 0.05]
}
Agent/Message/Sender instproc randomize v {
return [expr $v * (1.0 + [ns-random] / 2147483647.)]
}
Agent/Message/Sender instproc timeout {} {
global ns
$self send "probe [$ns now]"
$self sched [$self randomize 0.05]
}
Agent/Message/Sender instproc handle msg {
set type [lindex $msg 0]
if { $type == "congested" } {
$self decrease
} else {
$self increase
}
}
Agent/Message/Sender instproc increase {} {
$self instvar cbr_
set delta [$cbr_ set interval_]
set delta [expr 1.0 / (1.0 / $delta + 100)]
$cbr_ set interval_ $delta
}
Agent/Message/Sender instproc decrease {} {
$self instvar cbr_
set delta [$cbr_ set interval_]
set delta [expr 2 * $delta]
$cbr_ set interval_ $delta
}
Agent/Message/Receiver instproc init {} {
$self next
$self instvar mon_ congested_
set mon_ [new Agent/LossMonitor]
$mon_ proc log-loss {} "$self log-loss"
set congested_ 0
}
Agent/Message/Receiver instproc log-loss {} {
global ns
$self instvar congested_
if !$congested_ {
$self send "congested 0"
set congested_ 1
}
}
Agent/Message/Receiver instproc handle msg {
$self instvar congested_
if $congested_ {
set congested_ 0
} else {
$self send "uncongested [lindex $msg 1]"
}
}
proc build_conn { from to startTime } {
global ns
set src [new Agent/Message/Sender]
set sink [new Agent/Message/Receiver]
$ns attach-agent $from $src
$ns attach-agent $to $sink
$ns connect $src $sink
$ns attach-agent $from [$src set udp_]
$ns attach-agent $to [$sink set mon_]
$ns connect [$src set udp_] [$sink set mon_]
$ns at $startTime "[$src set cbr_] start"
return [$src set udp_]
}
set f [open out.tr w]
$ns trace-all $f
set nf [open out.nam w]
$ns namtrace-all $nf
build_topology $ns FIFO
set c1 [build_conn $n0 $n3 0.1]
$c1 set class_ 1
set c2 [build_conn $n1 $n3 0.1]
$c2 set class_ 2
$ns at 5.0 "finish"
proc finish {} {
global ns f nf
$ns flush-trace
close $f
close $nf
#XXX
puts "running nam..."
exec nam out.nam &
exit 0
}
$ns run
|
