/usr/share/doc/nam/examples/edu/B2-stop-n-wait-loss.tcl is in nam-examples 1.15-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
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 | # stop and wait protocol in congestion
# features : labeling, annotation, nam-graph, and window size monitoring
set ns [new Simulator]
$ns color 1 red
$ns trace-all [open B2-stop-n-wait-loss.tr w]
$ns namtrace-all [open B2-stop-n-wait-loss.nam w]
### build topology with 6 nodes
proc build_topology { ns } {
global node_
set node_(s1) [$ns node]
set node_(s2) [$ns node]
set node_(r1) [$ns node]
set node_(r2) [$ns node]
set node_(s3) [$ns node]
set node_(s4) [$ns node]
$node_(s2) color "red"
$node_(s4) color "red"
$node_(r1) color "blue"
$node_(r2) color "blue"
$node_(r1) shape "rectangular"
$node_(r2) shape "rectangular"
$ns at 0.0 "$node_(s1) label Stop&Wait"
$ns at 0.0 "$node_(s2) label CBR"
$ns at 0.0 "$node_(s3) label Stop&Wait"
$ns at 0.0 "$node_(s4) label CBR"
$ns duplex-link $node_(s1) $node_(r1) 0.5Mb 50ms DropTail
$ns duplex-link $node_(s2) $node_(r1) 0.5Mb 50ms DropTail
$ns duplex-link $node_(r1) $node_(r2) 0.5Mb 50ms DropTail
$ns duplex-link $node_(r2) $node_(s3) 0.5Mb 50ms DropTail
$ns duplex-link $node_(r2) $node_(s4) 0.5Mb 50ms DropTail
$ns queue-limit $node_(r1) $node_(r2) 2
$ns queue-limit $node_(r2) $node_(r1) 2
$ns duplex-link-op $node_(s1) $node_(r1) orient right-down
$ns duplex-link-op $node_(s2) $node_(r1) orient right-up
$ns duplex-link-op $node_(r1) $node_(r2) orient right
$ns duplex-link-op $node_(r2) $node_(s3) orient right-up
$ns duplex-link-op $node_(r2) $node_(s4) orient right-down
$ns duplex-link-op $node_(r1) $node_(r2) queuePos 0.5
$ns duplex-link-op $node_(r2) $node_(r1) queuePos 0.5
}
build_topology $ns
Agent/TCP set nam_tracevar_ true
### stop-n-wait protocol between s1 and s3 (Black)
set tcp [new Agent/TCP]
$tcp set window_ 1
$tcp set maxcwnd_ 1
$ns attach-agent $node_(s1) $tcp
set sink [new Agent/TCPSink]
$ns attach-agent $node_(s3) $sink
$ns connect $tcp $sink
set ftp [new Application/FTP]
$ftp attach-agent $tcp
$ns add-agent-trace $tcp tcp
$ns monitor-agent-trace $tcp
$tcp tracevar cwnd_
### CBR traffic between s2 and s4 (Red)
set cbr [$ns create-connection CBR $node_(s2) Null $node_(s4) 1]
$cbr set fid_ 1
### set operations
$ns at 0.1 "$ftp start"
$ns at 2.35 "$ftp stop"
$ns at 0.1 "$cbr start"
$ns at 2.35 "$cbr stop"
# $ns at 0.48 "$ns queue-limit $node_(r1) $node_(r2) 1"
$ns at 0.52 "$ns queue-limit $node_(r1) $node_(r2) 2"
$ns at 3.0 "finish"
### add annotation
$ns at 0.0 "$ns trace-annotate \"Stop and Wait with packet loss\""
$ns at 0.05 "$ns trace-annotate \"FTP starts at 0.1\""
$ns at 0.11 "$ns trace-annotate \"Send Packet_0\""
$ns at 0.30 "$ns trace-annotate \"Receive Ack_0\""
$ns at 0.45 "$ns trace-annotate \"Send Packet_1\""
$ns at 0.50 "$ns trace-annotate \"Packet_1 is lost\""
$ns at 0.55 "$ns trace-annotate \"Waiting for Ack_1\""
$ns at 1.34 "$ns trace-annotate \"Timout -> Retransmit Packet_1\""
$ns at 1.55 "$ns trace-annotate \"Receive Ack_1\""
$ns at 1.70 "$ns trace-annotate \"Send Packet_2\""
$ns at 1.90 "$ns trace-annotate \"Receive Ack_2 \""
$ns at 2.0 "$ns trace-annotate \"FTP stops\""
proc finish {} {
global ns
$ns flush-trace
puts "filtering..."
exec tclsh ../bin/namfilter.tcl B2-stop-n-wait-loss.nam
puts "running nam..."
exec nam B2-stop-n-wait-loss.nam &
exit 0
}
$ns run
|