Kamalio as registration server extensions as load balancer and to use Elastix servers for voice traffic and voice gateway ... .It can be three servers Kamalio and 5 servers Elastix Appliance, Also We would like to have A2billing for billing purpose because we are prepaid, also we would like to Required Device Provisioning development in this,
Cisco SPA Devices and Grandstream, Mediatrix
TO 600 simultaneous calls:
CPU: Quad Core 2.2 (2 processors)
RAM: 16 GB
Hard Drive: 1TB
Network Interface: 4 Gigabit ports
If you have better Recommendation as well please let me know,.
We will do the all the basic installations and You have to do Configurations and make sure reliable system ,.