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Re: [ns] large window size in satellite simulation




"Takeshi KITAHARA" wrote:
> I try  TCP over satellite(GEO) simulation.
> When I set large window, some packets drop.
> Why do packets drop?
> 
> I use following scripts.
> As the result of simulation of this script, 12packets dropped
> consecutively after 4[sec] from ftp start.  
> Could anyone tell me the reason ?
> 
> I wonder if this is concerned with "qlim"...

Hi Takeshi,

I am a new ns user. 
I study about TCP over LEO satellite network.

I think that the packets are dropped at n1's output queue.
In your scripts, n1's queue size is only 100(=opt(qlim)), 
but window size of tcp0 is 125 in maximum.
So, when the window size of tcp0 exceeds 100(at about 4[sec]), 
the packets are dropped.

Best Regards
-----------------------------------------
Hiroshi TSUNODA  E-mail: [email protected]