On Jun 4, 2009, at 9:32 AM, Apostolos Pantsiopoulos wrote:

NOTE No 1 : All the performance recommendations found in the wiki has
been applied. In fact only the essential modules that could make this
scenario work
were loaded.

What are you testing against? What OS, Hardware, Distro and such?

NOTE No 2 : I tried using asterisk (as a point of reference - don't get
me wrong - I am not trying to start a flame war here). And it succeeded
doing on the same hardware 60 calls/sec with a channel limit of 400
sim. calls using only 50% of the cpu (maximum). No under any
circumstances I have seen the behavior above (this inability to hang
call legs in a timely manner). Even when I pushed asterisk to the limits
(80 calls per second 600 max call limit) and it started failing on some
calls it never failed to hangup the calls for both legs on exactly 10 secs.

Load testing is a science and you can do it wrong most of the time unless you know exactly what you're doing. If you're going against the default dialplan its heavy and not something I would load test against.

NOTE No 3 : As you can tell I was using a very small machine for my
tests. When I moved the same tests to larger installations (Quad Core
Opterons and Xeons) I got proportional results to the above.

What are you testing on now? Hope its 64bit.