Patent ID: 8655402

Claim:
A Private Branch Exchange (PBX) system, comprising: a main exchange center connected to a plurality of extension units to provide a private Short Message Service (SMS) to the extension units, determining a type of a main line interface via which a ring signal is received and whether the ring signal received via the corresponding main line type is received from an SMS center (SMSC), and notifying an SMS processor of the receipt of an SMS message when it is determined that the ring signal is received from the SMSC; and the SMS processor mutually matching originating or destination unit information differently contained in the SMS message according to the main line interface type of the main exchange center with extension unit information corresponding to the information to construct a table from extension unit-matching information, establishing a communication path with the SMSC via the main exchange center to receive an SMS message according to the notification of receipt of an SMS from the main exchange center, extracting the originating unit information or destination unit information contained in the received SMS message and differently constituted according to the main line interface type, obtaining extension unit information corresponding to the extracted originating unit information or destination unit information from the extension unit information constituted in the form of a table, and distributing the received SMS message to an extension unit corresponding to the obtained extension unit information via the main exchange center.