Re: ns performance

[Polly Huang <huang@catarina.usc.edu>]

Christian,

With session mode multicast and hierarchial routing, a 5000 node
simulation will take about 170 MB just to create the topology and routing
table.  As for the 10000 multicast messages, the memory consumption
depends on how many of them are in transit (flowing through the topology)
at a time (should be bounded by the bandwidth*delay product of the entire
topology though).

Run time depends on how much physical memory is available. As soon as the
physical memory runs out, the machine will suffer from swapping and it
could take from hours to days to finish the simulations. 

Note that queuing delay is ignored in session mode simulation. If
congested network is required in your experiments, you should avoid using
session mode. 

Excuse me for being a little hand-wavy here. The time and memory
consumption does rely on many factors.

Cheers,
-Polly

On Wed, 12 Aug 1998, Christian Maihoefer wrote:

> Hi,
> 
> I want to use ns to simulate a network with about 5000 multicast nodes
> and about 10000 multicast messages. Can someone please tell me if such a
> large network can be simulated with ns and how long one simulation of
> this scenario approximatly runs (order of seconds, hours or days). I
> want to use a Pentium-150 Computer with Linux or Windows NT.
> 
> Thanks for your help,
> Christian
>