Re: [ns] FTP and CBQ

[Carlos Alberto Kamienski <cak@cin.ufpe.br>]

> I'm trying to use FTP with CBQ
> Do I have to set a class for FTP and another one for the ACKs.

Yes, you need configure CBQ in both sides if you are using a duplex-link.
CBQ don not create queues by default. Another option is to set a
CBQ simplex-link and a DropTail simplex-link in the opposite side.

> I tried the scrip below but it keeps giving me the following error:

This is because a packet arrives at the link and does not find a queue
for it (bound to the same fid_)

Carlos

> 
> Any help will be appreciated.
> Nasser
> 
> 
> ns: _o114 unknown-flow 1 0 0:
>     (_o114 cmd line 1)
>     invoked from within
> "_o114 cmd unknown-flow 1 0 0"
>     invoked from within
> "catch "$self cmd $args" ret"
>     (procedure "_o114" line 2)
>     (SplitObject unknown line 2)
>     invoked from within
> "_o114 unknown-flow 1 0 0"
> 
> #=========== related script =========
> # ........
> 
> #Create six nodes
> set fs [$ns node] ;# node 0
> set fd [$ns node] ;# node 1
> set ps [$ns node] ;# node 2
> set pd [$ns node] ;# node 3
> set r0 [$ns node] ;# node 4
> set r1 [$ns node] ;# node 5
> 
> #Create links between the nodes
> # ........
> 
> #Set the CBQ
> $ns duplex-link $r0 $r1 10Mb 20ms CBQ
> 
> set cbqlink1 [$ns link $r0 $r1]
> set cbqlink2 [$ns link $r1 $r0]
> 
> #Set the CBQClass
> set topclass [new CBQClass]
> $topclass setparams none 0 1 auto 4 2 0
> 
> set classe_0 [new CBQClass]
> set queue_0 [new Queue/DropTail]
> $classe_0 install-queue $queue_0
> $classe_0 setparams $topclass 1 1 auto 1 1 0
> 
> set classe_1 [new CBQClass]
> set queue_1 [new Queue/DropTail]
> $classe_1 install-queue $queue_1
> $classe_1 setparams $topclass 1 1 auto 1 1 0
> 
> $cbqlink1 insert $topclass
> $cbqlink1 insert $classe_0
> $cbqlink2 insert $classe_1
> 
> $cbqlink1 bind $classe_0 0 ; # fid 0
> $cbqlink2 bind $classe_1 1 ; # fid 1
> 
> #Create a TCP agent and attach an FTP to it at node fs
> set tcp0 [new Agent/TCP]
> $ns attach-agent $fs $tcp0
> $tcp0 set fid_ 0
> set sink0 [new Agent/TCPSink]
> $ns attach-agent $fd $sink0
> $sink0 set fid_ 1
> $ns connect $tcp0 $sink0
> 
> set ftp0 [new Application/FTP]
> $ftp0 attach-agent $tcp0
> 
> 
> #Schedule events
> $ns at 0.0 "$ftp0 start"
> $ns at 3.0 "$ftp0 stop"
> 
> ======= end of script ===============
> 
>