It’s always been a big challenge to make large volume concurrent calls or install many telephony interface cards with an asterisk server. And, OpenVox spends a lot of time in working on this challenge and finally we’ve found a way by reducing interrupt frequency and the I/O operations to make it work.
OpenVox D430 is now the leading 4 port T1/E1/J1 interface card which supports PCI or PCI-E bus and provides some advanced features such as adjusting the interrupt number, modifying the interrupt frequency, supporting firmware upgrade onsite, etc. OpenVox has been continuously improving the firmware of D430 to achieve better performance. Now, the firmware 1.5 enables the asterisk server to support up to 32 E1 interfaces which means it can have 960 SIP-to-TDM concurrent calls.
We have released the detailed installation and implementation steps on it and please check our wiki site HERE for more info.