US 11,990,990 B2
Relay device and communication system
Toshiyuki Nakayasu, Tokyo (JP); Sachiko Taniguchi, Tokyo (JP); and Ryusuke Kawate, Tokyo (JP)
Assigned to MITSUBISHI ELECTRIC CORPORATION, Tokyo (JP)
Filed by Mitsubishi Electric Corporation, Tokyo (JP)
Filed on Mar. 31, 2022, as Appl. No. 17/710,070.
Application 17/710,070 is a continuation of application No. PCT/JP2020/022691, filed on Jun. 9, 2020.
Claims priority of application No. 2019-224503 (JP), filed on Dec. 12, 2019.
Prior Publication US 2022/0224430 A1, Jul. 14, 2022
Int. Cl. H04J 3/06 (2006.01); H04L 7/04 (2006.01); H04L 7/10 (2006.01)
CPC H04J 3/0658 (2013.01) [H04L 7/042 (2013.01); H04L 7/10 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A relay device comprising: a plurality of ports to receive frames; and
processing circuitry to transfer a frame received at one of the ports to at least one of the ports,
wherein the processing circuitry has a filtering function for blocking frames other than a clock-time synchronization frame during transfer involving the port selected from the ports, the clock-time synchronization frame being used for synchronizing clock time wherein as a result of using the filtering function, the processing circuitry discards a first frame when the first frame is not the clock-time synchronization frame, the first frame being a frame received by the selected port,
wherein the processing circuitry applies the filtering function to the frame received by a port other than the selected port, and
wherein the processing circuitry does not transfer a second frame to the selected port when the second frame is not the clock-time synchronization frame, the second frame being a frame received by a port other than the selected port.