Network system priority control method

A priority control method of a network system for providing a communication between terminals comprising a first exchange for accommodating a plurality of first terminals, a first connecting device connected with the first exchange, an IP network connected with the first connecting device, a second connecting device connected with the IP network, and a second exchange for accommodating at least one of a second terminal, the second exchange is connected with the second connecting device, wherein

• the first exchange holds priority classes corresponding to each of the first terminals;
• the first connecting device holds service types corresponding to each of the priority classes held in the first exchange;
• the first exchange, when a call is set between any one of the first terminals as a call-out terminal and the second terminal as a call-in terminal through the IP network, notifies the first connecting device of a priority class corresponding to the first terminal as a call-out terminal;
• the first connecting device reads ant a service type corresponding to the notified priority class, saves the read out service type;
• and
• the first connecting device, when transmitting packers comprising data from the first terminal as the call-out terminal to the IP network after the call is established, sets the saved service type to the packers, thereby, priority control according to the service type set to the packets is performed in the IP network,
• wherein the first connecting device notifies the second connecting device of the read out service type to the second connecting device;
• the second connecting device saves the service type notified from the first connecting device;
• the second connecting device, when transmitting packets comprising data from the second terminal as a call-in terminal to the IP network after the call is established, sets the saved service type to the packets, thereby, priority control according to the service type set to the packets is performed in the IP network,
• wherein the second exchange holds a priority class corresponding to the second terminal;
• the second connecting device holds a service type corresponding to the priority class held in the second exchange;
• the second exchange notifies the second connecting device of the held priority class when a call is set between any one of the first terminals as a call-out terminal and the second terminal as call-in terminal;
• the second connecting device reads out a service type corresponding to the priority class notified from the second exchange;
• and
• the second connecting device compares the service type notified from the first connecting device and the service type read out from the second connecting device, saves the service type read out from the second connecting device instead of the service type notified from the first connecting device if the service type read out from the second connecting device is higher than the service type notified from the first connecting device.