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AssigneesIndustrial Technology Research Institute, National Chiao Tung University
InventorsMing-Feng Chang, Yi-Bing Lin, Ching-Feng Liang
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Disclosed is a method and apparatus applicable to an interface between PSTN and PTN for telephone routing. The interface includes a branch switch, a key system, a network branch switch, and media gateway, etc. The telephone routing method and apparatus of the present invention creates, maintains, and utilizes a call-back routing table to enable a specified PSTN user to call the callback external leased line to reach a specified PTN user in a one-stage dialing manner. The process of one-stage dialing includes PTN call origination to PSTN, PSTN call origination to PTN, and callback tag insertion in the call-back routing table. The call-back routing table consists of a plurality of call-back tags. Each call-back tag consists of at least a data triple, i.e. PTN user identifier, PSTN called party telephone number, and callback leased line identifier.
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:
An apparatus for telephone routing between a public switched telephone network (PSTN) and a private telephone network (PTN), comprising:
Dependencies are inferred from the claim text.