| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To prevent buffer overflow in a transmission buffer, and prevent discard of a MAC (Media Access Control) frame between packet transfer apparatuses in which clock difference may occur. <P>SOLUTION: The apparatus extracts a transmission clock frequency from the received MAC frame, and compares clock difference from a clock frequency in the apparatus. It embeds a number of a port receiving the frame in a preamble of the MAC frame, and the transmission side discriminates a reception port receiving the MAC frame. A control unit 1214 determines reception of the MAC frame whose transmission clock frequency is higher than the clock frequency in the apparatus based on the clock difference corresponding to the port number, and when vacant capacity of the transmission buffer (1208) is smaller than or equal to a predetermined threshold value, it changes an interval between MAC frames (IFG) output from the transmission buffer (1208) to an interval according to the clock difference, and makes output timing of the MAC frame faster. <P>COPYRIGHT: (C)2010,JPO&INPIT</p> |
