Re: Re: Re: [ns] Priority Queuing and CAR

[liu yong <engp1130@nus.edu.sg>]

hi ,
    Maybe you should read the source code if you want to know the details of the queuing.Try to read the ~ns2/tcl/ns-lib.tcl and read the Simulator instproc duplex-link{}.This instproc invokes the simplex-link{} in the same file. In this proc you will find there is no switch item for PriQueue. That is the reason for error of your script file.
So you should add some code here for the use of PriQueue according to the other Queue as an example.This is only my suggestion and I have never try it.
Good luck,
Liu Yong 

Hi Liu, 

I think that must be what I am searching for, but how can I configure it?

$ns duplex-link $n1 $nagr 200kb 100ms DropTail 

works pefectly, but

$ns duplex-link $nagr $nfin 300kb 100ms PriQueue

doesn't work at all, it gives erros when compiling.

Could you give me an example on how to configure it?

Is there somewhere where I can find the details of queue-scheduling on NS (chapter 7 of the NS manual is not enough at all, since the instructions lare listed, but they are not deeply explained nor are the parameters explained at all). Is there any specific resource of sintaxis or examples on that: PQ, CBQ/WFQ, ...

Thanks a lot. I would greatly appreciate anybody's help.

Jorge

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There is a PriQueue which is the subclass of the drop tail.I am not sure it is the exact one you want. 
            Good Luck. 
            Hi all, 
            I've read most of the NS documentation, specially the part about scheduling. It looks like NS has RED, FQ, SFQ, CBQ,
            .. but I have not been able to find PQ (Priority Queuing). By PQ I mean a queue in which "important packets" are always
            preferred over "routine packets", so a "routine packet" is never sent if there is an "important packet" in the queue. I
            thought there must surely be a way to model that with NS, as much more complex scheduling techniques have been
            implemented. 
            How can I simulate PQ? Is it somewhere with a different name? Can it be modeled as a special case of other
            implemented scheduling techniques? 
            Besides, I need to simulate CAR (policing), which means transmiting data using a token bucket limitation. Can I do that
            with NS? 
            Thanks a lot and best regards, 
            Jorge Manrique 
            liu yong 
            engp1130@nus.edu.sg 

            liu yong
            engp1130@nus.edu.sg