Re: [ns] Results interpretation

[Milind Dilip Kopikare <kopi@stanford.edu>]

HI Andrea,
  Yes, you can record the cwnd of an agent into an output file. write a
proc{} and keep calling it after say every 0.1 sec. Inside the proc a line
like
	for {set i 0} {$i <= [expr $numtcpsrc-1]} {incr i} {
            set cwnd($i)   [$tcp($i)   set cwnd_]
	    puts $f($i) "$now $cwnd($i)" 

	}

will put the required output in the file.

-milind



On Sat, 18 Nov 2000, Andrea Josi wrote:

> Hi everybody,
> i've just begun running simulations with NS,
> i don't know how to get informations from the
> simulations' results; to be more specific:
> 
> * how can i read trace files ?
>   all the simulations that i've run included a call
>   to either NAM or XGRAPH, so the output of the simulation
>   was an animation or a graph, i would like to get to read
>   something like
>   + 1.39117 3 4 exp 1000 ------- 0 0.0 4.0 13 159
>   + 1.394 3 4 cbr 1000 ------- 1 1.0 4.0 86 160
>   d 1.394 3 4 cbr 1000 ------- 1 1.0 4.0 86 160
>   - 1.394 3 4 exp 1000 ------- 0 0.0 4.0 9 147
>   r 1.396 3 4 cbr 1000 ------- 1 1.0 4.0 81 145
>   + 1.39969 3 4 exp 1000 ------- 2 2.0 4.0 60 161
> 
> * XGRAPH : wich quantities can be displayed ?
>   for instance, in Marc Greis' tutorial i've found
>   proc record {} {....
>   ...................
>   set bw0 [$sink0 set bytes_]
>   ............ }
>   Are bytes and packets the only quantities i can record ?
>   Can i record the parameters that characterize an agent ?
>   (for example, can i record the quantity cwnd of a TCP agent ?)
> 
> * NAM : what data can i collect by watching a NAM animation ?
>   how do i have to read the sequence of lines that appears
>   by clicking on a link and selecting the bandwidth of the link ?
> 
> * Am i ignoring other ways to interpret the output of a simulation ?
>   If i have to add some lines to my scripts i would appreciate if
>   someone sent me some of his own tcl scripts.
> 
> Please help me !!!
> Thanks in advance,
>                         Andrea Josi.
> 
> 
> 
> 
>