Hi everybody,
i‘m using ns-allinone-2.35 at CYGWIN_NT-6.1 inagtech 1.7.11(0.260/5/3)
2012-02-24 14:05 i686 Cygwin,
and start with `Marc Greis' Tutorial for the UCB/LBNL/VINT Network Simulator
"ns"`.
i write down the example in Section V as following,
# first of all, create a simulator object
set ns [new Simulator]
# open a file for writing which is going to be used for the nam trace data
set nf [open example2.nam w]
$ns namtrace-all $nf
# 'finish' procedure that closes the trace file and starts nam
proc finish {} {
global ns nf
$ns flush-trace
# close the trace file
close $nf
# execute nam on the trace file
exec nam example2.nam &
exit 0
}
# create four nodes
set n0 [$ns node]
set n1 [$ns node]
set n2 [$ns node]
set n3 [$ns node]
# create three duplex links between the nodes
$ns duplex-link $n0 $n2 1Mb 10ms DropTail
$ns duplex-link $n1 $n2 1Mb 10ms DropTail
$ns duplex-link $n3 $n2 1Mb 10ms DropTail
# layout these nodes to be nice
$ns duplex-link-op $n0 $n2 orient right-down
$ns duplex-link-op $n1 $n2 orient right-up
$ns duplex-link-op $n2 $n3 orient right
# create a UDP agent and attach it to node n0
set udp0 [new Agent/UDP]
# create a CBR traffic source and attach it to udp0
set cbr0 [new Application/Traffic/CBR]
$cbr0 set packetSize_ 500
$cbr0 set interval_ 0.005
$cbr0 attach-agent $udp0
# create a UDP agent and attach it to node n1
set udp1 [new Agent/UDP]
$ns attach-agent $n1 $udp1
# create a CBR traffic source and attach it to udp1
set cbr1 [new Application/Traffic/CBR]
$cbr1 set packetSize_ 500
$cbr1 set interval_ 0.005
$cbr1 attach-agent $udp1
# create a Null agent (a traffic sink) and attach it to node n3
set null0 [new Agent/Null]
$ns attach-agent $n3 $null0
# the two CBR agents have to be connected to the Null agent
$ns connect $udp0 $null0
$ns connect $udp1 $null0
# start and stop the CBR agents
$ns at 0.5 "$cbr0 start"
$ns at 1.0 "$cbr1 start"
$ns at 4.0 "$cbr0 stop"
$ns at 4.5 "$cbr1 stop"
# tell the simulator object to execute the 'finish' procedure after 5.0 seconds
of simulation time
$ns at 5.0 "finish"
# start the simulation
$ns run
When i execute this example,
$ns example2.tcl
Segmentation fault (core dumped)
Here is the stackdump file,
Exception: STATUS_ACCESS_VIOLATION at eip=6C7DDF0D
eax=00000000 ebx=20074520 ecx=202BCBE8 edx=00000000 esi=00000003 edi=00000000
ebp=0022AC98 esp=0022AC40
program=D:\cygwin\opt\ns-allinone-2.35\ns-2.35\ns.exe, pid 5644, thread main
cs=001B ds=0023 es=0023 fs=003B gs=0000 ss=0023
Stack trace:
Frame Function Args
0022AC98 6C7DDF0D (202A0410, 000001F4, 00000000, 00000000)
0022ACB8 6CA6D3E6 (202A0410, 000001F4, 00000000, 61152E7E)
0022ACD8 6C7D699D (202A4838, 000001F4, 6C7D7ED4, 202A0410)
0022ACF8 6C7D6E12 (202A4838, 00000000, 0022AD28, 20074520)
0022AD18 6C7D7F0A (202A4838, 6CB4F59F, 20073680, 6C9F3E24)
0022B148 6C7D67D0 (202A4838, 00000002, 0022B264, 6C973B37)
0022B178 6C970CD4 (202A4838, 20073568, 00000005, 0022B258)
0022B298 6C973CC2 (202A4688, 20073568, 00000003, 20074520)
0022B2C8 6C97A54D (202A4700, 20073568, 00000003, 20074510)
0022B348 6C97E645 (20073568, 00000003, 20074510, FFFFFFFF)
0022B4E8 6C9AF637 (20073568, 202BB960, 0000000B, 202AFAC8)
0022B528 6C9B9537 (20073568, 202AF9A8, 00000000, 00000000)
0022B6C8 6C9AF929 (20073568, 2013F398, 00000008, 00000001)
0022B738 6C9AB7D8 (20073568, 202AFAE0, 00000001, 6C9A9C11)
0022B758 6C9AB954 (2009EDB0, 20073568, 00000005, 20074428)
0022B7A8 6C97A7A8 (200879C8, 20073568, 00000005, 0022B888)
End of stack trace (more stack frames may be present)
But, the example from the tutorial executes well. What have I done wrong?
Thanks!
The example from the tutorial:
#Create a simulator object
set ns [new Simulator]
#Define different colors for data flows
$ns color 1 Blue
$ns color 2 Red
#Open the nam trace file
set nf [open out.nam w]
$ns namtrace-all $nf
#Define a 'finish' procedure
proc finish {} {
global ns nf
$ns flush-trace
#Close the trace file
close $nf
#Execute nam on the trace file
exec nam out.nam &
exit 0
}
#Create four nodes
set n0 [$ns node]
set n1 [$ns node]
set n2 [$ns node]
set n3 [$ns node]
#Create links between the nodes
$ns duplex-link $n0 $n2 1Mb 10ms DropTail
$ns duplex-link $n1 $n2 1Mb 10ms DropTail
$ns duplex-link $n3 $n2 1Mb 10ms SFQ
$ns duplex-link-op $n0 $n2 orient right-down
$ns duplex-link-op $n1 $n2 orient right-up
$ns duplex-link-op $n2 $n3 orient right
#Monitor the queue for the link between node 2 and node 3
$ns duplex-link-op $n2 $n3 queuePos 0.5
#Create a UDP agent and attach it to node n0
set udp0 [new Agent/UDP]
$udp0 set class_ 1
$ns attach-agent $n0 $udp0
# Create a CBR traffic source and attach it to udp0
set cbr0 [new Application/Traffic/CBR]
$cbr0 set packetSize_ 500
$cbr0 set interval_ 0.005
$cbr0 attach-agent $udp0
#Create a UDP agent and attach it to node n1
set udp1 [new Agent/UDP]
$udp1 set class_ 2
$ns attach-agent $n1 $udp1
# Create a CBR traffic source and attach it to udp1
set cbr1 [new Application/Traffic/CBR]
$cbr1 set packetSize_ 500
$cbr1 set interval_ 0.005
$cbr1 attach-agent $udp1
#Create a Null agent (a traffic sink) and attach it to node n3
set null0 [new Agent/Null]
$ns attach-agent $n3 $null0
#Connect the traffic sources with the traffic sink
$ns connect $udp0 $null0
$ns connect $udp1 $null0
#Schedule events for the CBR agents
$ns at 0.5 "$cbr0 start"
$ns at 1.0 "$cbr1 start"
$ns at 4.0 "$cbr1 stop"
$ns at 4.5 "$cbr0 stop"
#Call the finish procedure after 5 seconds of simulation time
$ns at 5.0 "finish"
#Run the simulation
$ns run
