I am using Asterisk 11.6 in CentOS 6.4 (64 bits) installed on HP G7 Server. When I start increasing the number of calls on the system, I observed abnormal behaviour in CPU usage as it was going beyond 1600%. Also when calls exceed the count of 30, voice quality starts dropping until you are unable to hear any.
I tried searching and putting a limit to the CPU usage up to 40% at first and than started increasing the limit, but whenever I start terminating the calls, Asterisk starts acting up and you either get a call full of distortions or with silence.
I have tried reinstalling Asterisk as well as OS. I have checked Asterisk 11 specifically on both x86 and x64. It is working fine on Asterisk 1.4 but I am not sure if it will work on any version beyond 11. If someone can provide assistance to resolve this as I need to use Asterisk 11 atleast.