Hitachi Metals, Ltd.

Hitachi Cable, Inc.

Apresia Systems, Ltd.

Kenji Aoshima

Koichiro Seto

Kazutoshi Kariya

Chikara Sawaguchi

A traffic amount measuring unit measures the traffic amount of frames received in each of cycles, and outputs the measured traffic amount for each cycle. A plurality of frequency counters are provided so as to correspond to a plurality of ranges, and retain frequencies of each of the plurality of ranges, respectively. A frequency counter updating unit determines in which of the plurality of ranges the traffic amount output for each cycle is included, and updates the frequency of the frequency counter corresponding to the range obtained by the determination result.

Network apparatus

A core switching device has a virtual path table and an address table, and selectively performs a PBB operation and a virtual path operation. The virtual path table retains a correspondence relation between a service instance identifier and two ports in a plurality of ports set in advance. The address table retains a correspondence relation between the plurality of ports and an encapsulation address. The core switching device relays an encapsulated frame based on the address table in the PBB operation and relays an encapsulated frame containing the service instance identifier retained in the virtual path table between the two ports retained in the virtual path table in the virtual path operation.

Switching device and relay system

A network switch is provided which can shorten a time required for switching-over to a backup route when a failure has occurred in a port for which an LAG is set. The network switch includes a failure detection unit for detecting a port failure, and a forced transfer processing unit for, when a failure is detected in a port at a transfer destination as a target in trying to transfer a received unicast frame and when an link aggregation group is set for a plurality of ports including the relevant port at the transfer destination, forcibly transferring the received unicast frame to another port for which the same link aggregation group as that set for the relevant port at the transfer destination is set.

Network switch

A switching hub for processing a VLAN frame transmitted through a transmission line of a ring network includes two ring ports connected to the transmission line of the ring network, and a forwarding processing mechanism for, when one of the two ring ports receives the frame and when a VLAN in which the received frame belongs is a VLAN only through both the ring ports, forwarding the frame to the other ring port without performing FDB learning on the frame.

Switching hub and ring network

A network relay device constituting a network includes a transmit/receive unit having plural ports; an FDB for storing as its registered contents at least a port identifier for identifying each of the plural ports, or an LAG port into which are grouped a specified number of the plural ports, a terminal identifier for identifying a terminal, and an FDB_ID for being associated with both the port identifier and the terminal identifier; and an FDB_ID table for storing the FDB_ID associated with the port identifier. When the registered contents of a specified port or LAG port stored in the FDB are erased, the stored FDB_ID associated with the port identifier identifying that port or LAG port is rewritten as another value.

Growing community of inventors

Tsuchiura, Japan

Kenji Aoshima