Patent ID: 7519732
Filing Date: 2009-04-14
Classification: H04L,H04M,Y10S

Abstract:
1. A routing service method in a Voice over Internet Protocol (VoIP) system using a stand-alone gateway interworking with a Public Switch Telephone Network (PSTN), comprising the steps of: receiving a call service request over an incoming trunk from a calling private branch exchange (PBX) connected via the PSTN; determining in the stand-alone gateway whether a call service can be provided over an Internet using an internal database in response to the call service request from the calling PBX; and using a PSTN access code for rerouting a call in response to a service request and transmitting the call to the calling PBX via a roundabout outgoing trunk used with the incoming trunk in the stand-alone gateway when it is determined that the call service cannot be provided over the Internet.