[ns] TCP and CBQ?

Hi all,

I've been looking to replies about the same question. I understand the problem and I tried to write a simple script to demonstrate how it works. However I.m still getting the same error message:

ns: _o26 unknown-flow 1 0 0:
    (_o26 cmd line 1)
    invoked from within
"_o26 cmd unknown-flow 1 0 0"
    invoked from within
"catch "$self cmd $args" ret"
    (procedure "_o26" line 2)
    (SplitObject unknown line 2)
    invoked from within
"_o26 unknown-flow 1 0 0"

I'm attaching my code, please have a look and let me know if I'm doing something wrong. Any help will be appreciated.

BTW: I tried my code with FULL TCP and it works fine. Unfortunately I need to use one way TCP.

Thanks in Advance.

Nasser

Here is the code:

#Create a simulator object
set ns [new Simulator]

#Open the ns trace file
set nsf [pen out_test.txt w]
$ns trace-all $nsf

#Define the 'finish' procedure
proc finish {} {
global ns
$ns flush-trace
#Close the trace file
close $nsf
exit 0
}

#Create nodes
set n0 [$ns node]
set n1 [$ns node]

#Create CBQ link between the nodes
$ns duplex-link $n0 $n1 10Mb 20ms CBQ

#Configure the CBQ
set cbqlink1 [$ns link $n0 $n1]
set cbqlink2 [$ns link $n1 $n0]

#Set the CBQClass
set topclass [new CBQClass]
$topclass setparams none 0 1 auto 9 2 0

set class_0 [new CBQClass]
set queue_0 [new Queue/DropTail]
$queue_0 set limit_ 40
$class_0 install-queue $queue_0
$class_0 setparams $topclass 1 1 auto 8 1 0

set class_1 [new CBQClass]
set queue_1 [new Queue/DropTail]
$queue_1 set limit_ 40
$class_1 install-queue $queue_1
$class_1 setparams $topclass 1 1 auto 0 1 0

$cbqlink1 insert $topclass
$cbqlink1 insert $class_0
$cbqlink2 insert $topclass
$cbqlink2 insert $class_1

$cbqlink1 bind $class_0 0
$cbqlink2 bind $class_1 1

# create a TCP connection between n0 and n1
set tcp [new Agent/TCP]
$ns attach-agent $n0 $tcp
$tcp set fid_ 0
$tcp set window_ 85
set ftp [new Application/FTP]
$ftp attach-agent $tcp
set sink [new Agent/TCPSink]
$ns attach-agent $n1 $sink
$sink set fid_ 1
$ns connect $tcp $sink

#Schedule events
puts "... Simulation running ..."
$ns at 0.0 "$ftp start"
$ns at 3.0 "$ftp stop"
$ns at 3.5 "finish"

#Run the simulation
$ns run