I need some help in deciding about an SDK (Software Development Kit) that I found recently. It is called OZEKI VoIP SIP SDK, with SipX ECS support. In fact, it supports a nice array of PBX. Here is their website: http://voip-sip-sdk.com/p_29-how-to-...-ecs-voip.html
I think it is a good opportunity for me to create my own VoIP application. My question is, would you recommend using FreePBX or other PBX, like SipX ECS with this SDK? Which one has the best, reliable service?