Patent ID: 8593948

Claim:
A network device that is a first network device communicatively coupled to a second network device, the network device comprising: a processing unit configured to process frames received from the second network device; and a receive buffer configured to store therein the frames as received, wherein the processing unit sends the second network device a PAUSE frame in order to prevent shortage of the receive buffer from causing a loss of frames transmitted from the second network device, the PAUSE frame being a frame causing the second network device to stop transmitting the frames for a PAUSE period that is a time period set in the PAUSE frame, sends the second network device a test frame being a frame causing the second network device to return a frame, receives a response frame being a frame returned by the second network device in response to the test frame, acquires a test frame transmission start time that indicates a time point when processing for transmitting the test frame is started, acquires a response frame reception completion time that indicates a time point when processing for receiving the response frame is completed, receives a test frame reception completion time that is transmitted from the second network device and indicates a time point when the second network device completes processing for receiving the test frame, and a response frame transmission start time that is transmitted from the second network device and indicates a time point when the second network device starts processing for transmitting the response frame, calculates a PAUSE frame action delayed period that indicates a time period required from when the processing for transmitting the PAUSE frame is started until the second network device stops transmission of the frames, on basis of the following equation, PAUSE frame action delayed period=((Response frame reception completion time−Test frame transmission start time)−(Response frame transmission start time−Test frame reception completion time))/2, and sends the second network device the PAUSE frame in which a time period calculated based on the PAUSE frame action delayed period is set as the PAUSE period in order to prevent the shortage of the receive buffer from causing a loss of the frames transmitted from the second network device.