Our problem: We cannot terminate calls between dissimilar phone systems using VoIP.
We would appreciate any assistance on how to efficiently connect dissimilar phone systems from two different manufacturers with the right interface cards already installed. The dissimilar phone systems are Erickson BP128 and Index phone systems.
One approach to solving this is to get multiple SIP to PSTN gateways that based upon the dial plan, can direct the call to any of the other gateways. The gateways would connect to the existing PBX systems using the standard PSTN interfaces.
This was first published in May 2004