Fujitsu Corporation

Kunihiko Hamamoto

Hiroshi Kinoshita

Daisuke Nagai

Atsuko Higashitaniguchi

Shigeru Suzuyama

Takahiro Suetsugu

Shingo Suzumori

The disclosed apparatus includes a MAC learning table storing a MAC address and port identification information that uniquely identifies a port for transferring a frame to which the MAC address is assigned. The apparatus includes updating the MAC learning table, reading a MAC address of a link trace frame, transferring the link trace frame via a port determined based on the MAC learning table, storing a correspondence relationship of a predetermined MAC address and port identification information, saving a correspondence relationship set as an object to be deleted at a time of updating the MAC learning table, transferring the link trace frame, if there is no correspondence relationship relevant to the MAC address of the link trace frame in the MAC learning table, and sending a response frame to a switching hub which is an originator of the link trace frame with transfer of the link trace frame.

Link trace frame transfer program recording medium, switching hub, and link trace frame transfer method

In a data transmission method and apparatus which can perform a switchover of all of the main lines without requiring much construction cost, a transmission apparatus sets, upon frame transmission or reception, combinations of a plurality of main lines with virtual paths established so as to include at least a part of a bandwidth of the main lines in one or more protection lines as redundant configurations. Upon frame transmission, the apparatus copies frames received in the main lines, assigns identifiers of the redundant configurations to the copied frames, and transmits the copied frames to the virtual paths of the redundant configurations. Upon frame reception, the apparatus determines whether the main lines or the virtual paths forming the redundant configurations are valid, deletes the identifiers of the redundant configurations assigned to frames received from the protection lines, and determines whether the frames from which the identifiers have been deleted should be respectively discarded or transferred depending on validity or invalidity of the main lines.

Data transmission method and apparatus

Growing community of inventors

Fukuoka, Japan

Kunihiko Hamamoto