Patent ID: 7990956

Claim:
A voice communication system configured over an IP phone system, for enabling an analog telephone device and an IP phone device to perform voice communications through the IP phone system, and in the IP phone system, the IP phone device is able to receive a call corresponding to its IP phone account and to perform voice communications, the voice communication system, comprising: a communication mediation device, electrically coupled to the analog telephone device via a Private Automatic Branch Exchange (PABX), comprising: an analog-digital signal conversion module, for converting a telephone number dialed by the analog telephone device into a digital signal, and converting the digital signal from the IP phone system into an analog signal; a conversion module, for converting the telephone number in the digital signal into the corresponding IP phone account; and an IP phone module, for calling the IP phone device of the corresponding IP phone account through the IP phone system according to the IP phone account that is converted by the conversion module, thereby allowing the analog telephone device to proceed with voice communications with the IP phone device, wherein the analog telephone device is an extension telephone connected to the PABX and has an extension number, and configuring a plurality of communication lines between the PABX and the analog-digital signal conversion module of the communication mediation device, and the PABX having a main switchboard number, wherein the main switchboard number having the corresponding IP phone account, and the voice communication system, further comprising: a master control device, comprising: a status database, for storing a plurality of status data, wherein each status data is corresponding to each usage status of the main switchboard number corresponding to the communication lines, and the usage status is used for selection from busy and idle; an update module, for updating the usage status of the main switchboard number corresponding to the communication lines according to a notification message from the communication mediation device; an overflow database, for storing a plurality of overflow records, wherein each overflow record is using the main switchboard number to correspond with an overflow notification message; an overflow module, for querying for the usage status of the communication lines corresponding to the main switchboard number based on the status data in the status database, and if their status are all busy, then updating the overflow notification message corresponding to the main switchboard number in the overflow database; and a continuous overflow module, for querying the overflow database for the overflow notification message corresponding to the main switchboard number based on the overflow records in the overflow database, if the overflow notification messages are found at a predetermined frequency, then sending out a continuous overflow message.