Fujitsu Corporation

Toshihiro Ban

Masanori Kondo

Takashi Fukagawa

Akihiro Hata

Kazuhiro Minamimoto

Kazuhiro Ohnuma

Yasushi Nishine

Norihito Hama

A communication device includes a processor. The processor updates, when a port which is received a packet is connected to a first path or a second path, an identifier assigned to the packet from a value according to the path to a first value or a second value. The processor learns a correspondence relationship between a destination address of the packet and a transmission port by flooding the packet, and determines the transmission port based on the correspondence relationship. The processor updates, when the transmission port is connected to the first path or the second path, the identifier assigned to the packet of which the transmission port is determined to a value according to the first path or the second path. The processor discards the packet of which the identifier is updated to the second value by the first process and the transmission port is connected to the second path.

Communication apparatus and communication method

According to an aspect of an embodiment, a node apparatus used in at least part of nodes in a network formed by a plurality of nodes coupled in the shape of a ring, comprising: a working node function performing unit for performing functions as a working apparatus that selectively drops a frame destined for a terminal hosted by the node itself among frames transmitted on the ring and adds a frame from the terminal hosted by the node itself to frames transmitted on the ring; a back-up function performing unit for performing functions as a back-up apparatus that lets a frame destined for a terminal hosted by the node itself pass through to an adjacent node and discards a frame from the terminal hosted by the node itself; and a function selection unit for selectively enabling one of the working node function performing unit and the back-up function performing unit.

Ring node apparatus

An apparatus for transmitting terrestrial digital data using a synchronous-optical-network system or a synchronous-digital-hierarchy system includes a synchronous-difference calculating unit that calculates a synchronous difference between a standard signal used in the synchronous-optical-network system or the synchronous-digital-hierarchy system and a first synchronous signal that synchronizes with a leading position included in image data of the terrestrial digital data; and a transmission processing unit that transmits the synchronous difference together with the terrestrial digital data to a destination.

Method and apparatus for transmitting terrestrial digital signal

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Kawasaki, Japan

Toshihiro Ban