Re: [ns] Date: Mon, 2 Apr 2001 11:07:51 +0300

[Lloyd Wood <l.wood@eim.surrey.ac.uk>]

On Mon, 2 Apr 2001, Tsironis Fotis wrote:

>     I need your valuable help. I use the ns for my graduate project.
> I use the ns to simulate a simple network with a GEO satellite and two 
> ground terminals.
> I want to write a simple script to count the incoming bandwidth at the 
> receiver (using TCP, any version). Does anyone have anything like this?

See http://www.ee.surrey.ac.uk/Personal/L.Wood/ns/
'Measure TCP Throughput accurately'
for some hints.


> I already have such a script for UDP, but the sink object uses a 
> variable called "bytes_" which does not exist in TCPSink objects.What 
> can I do?

TCPSink really is something of a poor cousin; it needs a better
recv() function with some useful bound variables...


> And something more! I also need a script like the one above, with a 
> simplex GEO link and a dial-up terestrial link for the return traffic. 
> Is there anything available?

Since it's GEO, use 'normal' serial-type links and get the link delays
right for your terminal/satellite longitudes and latitudes. You can
then use the same serial-type links for the return traffic over the
dialup. (If you used the satellite extensions, you wouldn't be able to
add the dialup link.)

You may want to investigate use of simplex links.

L.

<L.Wood@surrey.ac.uk>PGP<http://www.ee.surrey.ac.uk/Personal/L.Wood/>