Internet telephone system, private branch exchange device and customer service scheduling method

An internet telephone system, comprising:

• a user device, comprising:
• a processing unit;
• and
• a transmission unit, connected to the processing unit;
• and
• a PBX device, comprising:
• a communication unit;
• an interactive voice response unit (IVR), connected to the communication unit;
• a control unit, connected to the communication unit and the interactive voice response unit;
• a distribution unit, connected to the control unit;
• and
• at least one service extension;
• wherein in a call accessing procedure,
• the processing unit of the user device sets a push token into a first SIP header of a first session initiation protocol message (SIP message);
• the transmission unit of the user device transmits the first session SIP message to the PBX device to place a call;
• when the communication unit of the PBX device receives the first session SIP message, the interactive voice response unit of the PBX device directs the call to the service extension;
• the PBX device determines whether the service extension is busy;
• and
• if the service extension is busy, the control unit of the PBX device records the push token and the service extension to a scheduled call of a queue list and records a scheduling status of the scheduled call as “pending”.

A PBX device, comprising:

• a communication unit;
• an interactive voice response unit, connected to the communication unit;
• a control unit, connected to the communication unit and the interactive voice response unit;
• and
• a distribution unit, connected to the control unit;
• wherein in a call accessing procedure,
• a user device sets a push token into a first SIP header of a first session initiation protocol message (SIP message);
• the user device transmits the first session SIP message to the PBX device to place a call;
• when the communication unit of the PBX device receives the first session SIP message, the interactive voice response unit of the PBX device directs the call to a service extension;
• the PBX device determines whether the service extension is busy;
• and
• if the service extension is busy, the control unit of the PBX device records the push token and the service extension to a scheduled call of a queue list and records a scheduling status of the scheduled call as “pending”.