Patent ID: 7627101
Filing Date: 2009-12-01
Classification: H04M,H04Q

Abstract:
1. A method for telephone routing between a private telephone network (PTN) and a public switched telephone network (PSTN), said method is applicable to an interface apparatus between said PSTN and said PTN, said interface apparatus connects to a least one PSTN by using a plurality of external lines, and also connects to a plurality of telephony devices via an intranet, when a PTN user make a call to a PSTN user, said telephone routing method comprises the steps of: (a) creating and inserting a new call-back tag into a call-back routing table including a plurality of call-back tags; (b) dividing all external lines connected to said PSTN into two sets, callback lines and non-callback lines; and (c) searching said call-back table for said new inserted call-back tag, and directly connecting a corresponding PSTN called party number of said PSTN user to a corresponding PTN caller identifier of said PTN user via one of said external lines in a one-stage dialing scheme.