CPU dimensioning on performance of Asterisk VoIP PBX

Voice over Internet Protocol (VoIP) has become the choice of small enterprises for voice and data integration in cost cutting measures and making use of IT resources more efficiently. In this research we show that there is a requirement for appropriately dimensioning the VoIP server system to make it appropriate in size and make room for future expansion. The tests were conducted on two systems for comparison and performance evaluation. Asterisk, the open source PBX of choice, was used to show that this is a fast maturing software system and is ready for main stream VoIP implementation. We measured only the effect of number of concurrent calls on the CPU. Further, our preliminary studies demonstrate that the number of concurrent calls is mostly dependent on the CPU power.