Re: RED

[Kedarnath Poduri <kpoduri@BayNetworks.COM>]

One of my 'learned' friends has just warned me that  one can never assure
that a peace of code has no bugs. I have to agree with him. I wasn't
assuring that 
red code has no bugs. Just that it does change it's behavior with the
change in linterm_ (may I add) correctly?

Kedar

At 01:08 PM 12/14/98 -0800, you wrote:
>
>Hi,
>One think I can assure is that the red.cc has no bugs and works fine.
>I don't know if they have changed it in the latest version but the variable
>should be linterm_ not Linterm_. It's worth a check.
>
>Kedar
>
>At 01:15 PM 12/14/98 +0100, Bodog Gyula wrote:
>>Hi,
>>
>>I have enough traffic. I used 8 and 32 FTP flow.
>> In my simulation, I used the ECN bit to notify
>>congestion. As I looked the result (queue length, avg queue length), there's
>>congestion.
>>My problem is:
>>
>>When I change the Linterm_ parameter from 4 to 100, result doesn't change.
>>I think, in this case, t should see the change in the result, but it doesn't
>>change.
>>
>>Here my simulation script:
>>
>>
>>
>>set ns [new Simulator]
>>
>>set n0 [$ns node]
>>set n1 [$ns node]
>>set n2 [$ns node]
>>set n3 [$ns node]
>>
>>Queue/RED set thresh_ 20
>>Queue/RED set maxthresh_ 80
>>Queue/RED set q_weight_ 0.002
>>Queue/RED set setbit_ true
>>
>>$ns simplex-link $n0 $n1 10M 0ms RED
>>$ns simplex-link $n1 $n2 45M 0ms DropTail
>>$ns duplex-link $n1 $n3 20M 0ms DropTail
>>$ns simplex-link $n2 $n3 20M 10ms DropTail
>>$ns simplex-link $n3 $n0 20M 10ms DropTail
>>
>>$ns queue-limit $n0 $n1 240
>>
>>Simulator instproc get-link {node1 node2} {
>> $self instvar link_
>> set id1 [$node1 id]
>> set id2 [$node2 id]
>> return $link_($id1:$id2)
>> }
>>
>> set l [$ns get-link $n0 $n1]
>> set q [$l queue]
>> 
>>$q set Linterm_ 4 
>>
>>set qred [$l queue]
>>set avg [open avg w]
>>
>>proc avgqueue {qred isti} {
>>global ns avg status
>>
>>set maxpr [$qred set Linterm_]
>>set egz [$qred set ave_]
>>set cur [$qred set curq_]
>>set prob [$qred set prob1_]
>>set curt [$ns now]
>>
>>puts $avg [format "%9.3f %9.3f %9.3f %9.3f %9.3f" $curt $egz $cur $prob
>>$maxpr]
>>
>>$ns at [expr $curt + $isti] "avgqueue $qred $isti"
>>}
>>
>>for {set i  0} {$i <12 } { set i [expr $i+0.001]}  {
>>$ns at $i "avgqueue $qred 12"
>>}
>>
>>
>>Agent/TCP set packetSize_ 1000
>>Agent/TCP set bugFix_ false
>>Agent/TCP set window_ 32K
>>Agent/TCP set ecn_ true
>>
>>for {set i 0} {$i <8} {set i [expr $i+1]} {
>>
>>set tcp(i) [new Agent/TCP/Reno]
>>set snk(i) [new Agent/TCPSink]
>>$ns attach-agent $n0 $tcp(i)
>>$ns attach-agent $n2 $snk(i)
>>$ns connect $tcp(i) $snk(i)
>>set ftp(i) [$tcp(i) attach-source FTP]
>>$ns at 0.0 "$ftp(i) start"
>>$ns at 12.0 "$ftp(i) stop"
>>}
>>
>>
>>for {set i 0} {$i <24} {set i [expr $i+1]} {
>>
>>set tcp(i) [new Agent/TCP/Reno]
>>set snk(i) [new Agent/TCPSink]
>>$ns attach-agent $n0 $tcp(i)
>>$ns attach-agent $n2 $snk(i)
>>$ns connect $tcp(i) $snk(i)
>>set ftp(i) [$tcp(i) attach-source FTP]
>>$ns at 4.0 "$ftp(i) start"
>>$ns at 8.0 "$ftp(i) stop"
>>}
>>
>>$ns at 12 "finish"
>>
>>
>>proc finish {} {
>>
>>  
>>        global ns
>>        exit 0
>>
>>}
>>
>>                          
>>
>>$ns run
>>
>>
>>Thanks in advance
>>
>>
>>
>> * * * * * * * * * * * * * * * * * * * * * * * * * * * *  
>> *    Gyula Bodog                                      *
>> *     e-mail: s6356bod@ural2.hszk.bme.hu              *
>> *     tel.: (06 1) 3-691-839                          *
>> *     Student at Technical University of Budapest     *
>> *                                                     *
>> * * * * * * * * * * * * * * * * * * * * * * * * * * * *
>>
>>
>>
>