Re: LAN routing ?

[Yuri Pryadkin <yuri@who.isi.edu>]

Your script works for me, I can see all three flows.  And you don't
need '$ns compute-routes' in the middle, however it doesn't hurt.  I
can email you the nam trace file I get, if you like.

 -Yuri

Apinun Tunpan <apinun@wam.umd.edu> writes:

> Hello,
> 
>  I have some problems with LAN routing.  I use ns-allinone-2.1b5.
>  I run ns on SunOS 5.6 (Solaris).
> 
>  My test configuration is as follows:
>  
>   na    nb
>   |     |
>   n0    n2
>   |     |
>   +-----+
>   |     |
>   n1    n3
> 
>  Here n0,n1,n2,n3 are nodes in a 802_3 LAN.
>  na and nb are external nodes which interact with nodes inside the LAN.
>  I want to have three ftp traffic flows:  n0->nb, nb->n1 and nb->na.
>        
>  The problem is that the only traffic flow that gets through 
>  in both directions (data/ack) was  nb->n1 (as seen from nam --
>  you may try to diable the 'start' statement of each ftp flow 
>  and see the result).
> 
>  The script for the simulation is given below
> 
>  Is there any routing statement I should add to the script ?
>  or is it a bug ? or is it a problem with my own ns build  ?
> 
> Thanks,
> Apinun.
> 
> 
> == cut here ==
> 
> set ns [new Simulator]
> set f [open out.nam w]
> $ns namtrace-all $f
> 
> set n0 [$ns node]
> set n1 [$ns node]
> set n2 [$ns node]
> set n3 [$ns node]
> 
> set nodelist_ "$n0 $n1 $n2 $n3"
> 
> set na [$ns node]
> set nb [$ns node]
> 
> $ns duplex-link $na $n0  10Mb 20ms DropTail
> $ns duplex-link $nb $n2  10Mb 20ms DropTail
> 
> $ns duplex-link-op $na $n0 orient down
> $ns duplex-link-op $nb $n2 orient down
> 
> set lan_ [$ns make-lan $nodelist_ 10Mb 1ms LL Queue/DropTail Mac/802_3 Channel]
> 
> $ns compute-routes
> 
> set tcp0 [$ns create-connection TCP/Reno $n0 TCPSink $nb 0]
> set tcp1 [$ns create-connection TCP/Reno $nb TCPSink $n1 1]
> set tcp2 [$ns create-connection TCP/Reno $nb TCPSink $na 2]
> 
> $tcp0 set window_ 128
> $tcp1 set window_ 128
> $tcp2 set window_ 128
> 
> set ftp0 [$tcp0 attach-app FTP]
> set ftp1 [$tcp1 attach-app FTP]
> set ftp2 [$tcp2 attach-app FTP]
> 
> $ns at 0.1 "$ftp0 start"
> $ns at 0.2 "$ftp1 start"
> $ns at 0.3 "$ftp2 start"
> 
> $ns at 30.0 "$ns halt"
> puts "running..."
> $ns run
> 
> puts "finishing..."
> $ns flush-trace
> close $f
> 
> == cut here ==