“Extension” - is the extension of the telephone line (PBX) or the Centrex system. It works as an association and allows calling to certain telephone sets without the necessity of dialing the telephone number, but only by dialing a short combination of digits, reaching the desired subscriber.
IXC Softwitch is a high performance scalable Class 4 VoIP Softswitch solution with user friendly GUI web interface, which enables secure large VoIP traffic flow over various IP networks.