US 2011/0299386 A1Published application

Apparatus and method for switching between redundant communication devices

AssigneeFujitsu Limited

InventorsKatsuhiko Negoto, Akihiro Kameda, Isamu Fukuda, Atsushi Morohashi, Toshifumi Inoue, Kiyohisa Hoshino, Nobuyuki Fukuda, Kenji Fukuda, Kazuhiro Yasuno

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Abstract

A packet is transmitted from a transmitting device to an active communication device which transmits a reception history identifying the received packets to the transmitting device. The transmitting device transmits an active-mode request message to a standby communication device when having failed to receive the reception history from the active communication device within a predetermined time period. Then, the standby communication device becomes a new active communication device, and the active communication device becomes an old active communication device. The new active communication device transmits to the transmitting device a switching request message for switching a destination of the packet from the old active communication device to the new active communication device. The transmitting device retransmits packets that have been transmitted from the transmitting device to the old active communication device and have failed to be received by the old active communication device, to the new active communication device.

Claims8

Dependent claims

An apparatus, comprising:

a transmitter configured to transmit a packet to one of redundant communication devices including an active communication device and a standby communication device, the active communication device being in an operational mode of an active mode and capable of receiving the packet from the apparatus, the standby communication device being in the operational mode of a standby mode;
a receiver configured to receive, from the active communication device, a reception history identifying packets that have been transmitted from the apparatus and have been successfully received by the active communication device;
and
a retransmission controller configured
to change a destination of the packet, from an old active communication device that has lastly stopped the active mode, to a new active communication device that has newly changed the operational mode from the standby mode to the active mode, upon receiving from the new active communication device a switching request message for changing a destination of the packet from the old active communication device to the new active communication device, and
to determine retransmission packets that are to be retransmitted to the new active communication device, wherein
packets that have been transmitted from the apparatus to the old active communication device and have failed to be received by the old active communication device, are determined as the retransmission packets by comparing the reception history of the old active communication device with a transmission history identifying packets that have been transmitted from the apparatus to the old active communication device, and
the transmitter transmits the determined retransmission packets to the new active communication device.

5 more elements

An apparatus being operated as one of redundant communication devices for handling a packet received from a transmitting device, the redundant communication devices including an active communication device and a standby communication device, the active communication device being in an operational mode of an active mode and capable of receiving the packet from the transmitting device, the standby communication device being in the operational mode of a standby mode, the apparatus comprising:

a receiver configured to receive the packet from the transmitting device;
a mode controller configured to change the operational mode of the apparatus;
and
a switching request controller configured to transmit a switching request message to the transmitting device when the mode controller changed the operational mode of the apparatus from the standby mode to the active mode, the switching request message requesting the transmitting device to change a destination of the packet, wherein, in the case of the apparatus being in the standby mode,
the mode controller changes the operational mode of the apparatus from the standby mode to the active mode so that the apparatus becomes a new active communication device, when the apparatus receives an active-mode request message from the transmitting device,
the switching request controller transmits to the transmitting device the switching request message for requesting the transmitting device to change the destination of the packet from the active communication device to the new active communication device, and
the receiver receives, from the transmitting device, packets that have been transmitted from the transmitting device to the active communication device and have failed to be received by the active communication device.

4 more elements

A method for switching between redundant communication devices that handle a packet received from a transmitting device, the redundant communication devices including an active communication device and a standby communication device, the active communication device being in an operational mode of an active mode and capable of receiving the packet from the transmitting device, the standby communication device being in the operational mode of a standby mode, the method comprising:

transmitting, by the transmitting device, a packet to the active communication device;
transmitting, by the active communication device, to the transmitting device a reception history identifying packets that have been transmitted from the transmitting device to the active communication device and have been successfully received by the active communication device;
determining, by the transmitting device, that the active communication device has stopped the active mode thereof and has become an old active communication device when the transmitting device has failed to receive a next reception history from the active communication device within a predetermined time period after lastly receiving a reception history;
transmitting, by the transmitting device, to the standby communication device an active-mode request message for requesting the standby communication device to shift to the active mode;
changing, by the standby communication device, the operational mode thereof from the standby mode to the active mode so that the standby communication device becomes a new active communication device, when the standby communication device receives the active-mode request message;
transmitting, by the new active communication device, to the transmitting device a switching request message for switching a destination of the packet from the old active communication device to the new active communication device;
determining, by the transmitting device, packets that have been transmitted from the transmitting device to the old active communication device and have failed to be received by the old active communication device, based on the reception history received from the old active communication device;
and
retransmitting, by the transmitting device, the determined packets to the new active communication device.

6 more elements

A method for switching between redundant communication devices for handling a packet received from a transmitting device, the redundant communication devices including an active communication device and a standby communication device, the active communication device being in an operational mode of an active mode and capable of receiving the packet from the transmitting device, the standby communication device being in the operational mode of a standby mode, the method comprising:

transmitting, by the active communication device, to the standby communication device a reception history at predetermined intervals, the reception history identifying packets that have been transmitted from the transmitting device to the active communication device and have been successfully received by the active communication device;
determining, by the standby communication device, that the active communication device has stopped the active mode thereof and has become an old active communication device, when the standby communication device has failed to receive a next reception history from the active communication device within a predetermined time period after lastly receiving a reception history;
changing, by the standby communication device, the operational mode from the standby mode to the active mode so that the standby communication device becomes a new active communication device;
transmitting, by the new active communication device, to the transmitting device a switching request message including the reception history of the old active communication device, the switching request message requesting the transmitting device to switch a destination of the packet from the old active communication device to the new active communication device;
determining, by the transmitting device, packets that have been transmitted from the transmitting device to the old active communication device and have failed to be received by the old active communication device, based on the reception history included in the switching request message;
and
retransmitting, by the transmitting device, the determined packets to the new active communication device.

4 more elements

Dependencies are inferred from the claim text.