Patent ID: 8274907

Claim:
A network device for establishing quality of service (QoS) between two terminal devices, comprising: a transceiver module configured for receiving establishing requests, request responses, acknowledge messages, and QoS requests from any one of the two terminal devices; a state-machine setting module configured for setting a state of the network device according to a current state of the network device and messages received by the transceiver module, wherein the state of the network device comprises an idle state, an inviting state, a trying state, an acknowledge state, and a QoS state; and a processor that executes computerized instructions for the transceiver module and the state-machine setting module; wherein the state-machine setting module switches the state of the network device from the idle state to the inviting state when the transceiver module receives the establishing requests in the idle state; wherein the state-machine setting module switches the state of the network device from the inviting state to the trying state when the transceiver module receives the request response in the inviting state; wherein the state-machine setting module switches the state of the network device from the trying state to the acknowledge state when the transceiver module receives the acknowledge messages in the trying state; and wherein the state-machine setting module switches the state of the network device from the acknowledge state to the QoS state when the transceiver module receives the QoS request in the acknowledge state and the QoS is established successfully; wherein the transceiver module is further configured for receiving bye messages from any one of the two terminal device for ending a communication between the two terminal devices; wherein the state of the network device further comprises a QoS release state, and the state-machine setting module switches the state of the network device from the QoS state to the QoS release state when the transceiver module receives the bye messages in the QoS state.