Patents by Inventor Kazuo Sugai

Kazuo Sugai has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20120026894
    Abstract: The communication device has a frame transfer unit that executes frame transfer via the first communication link and the second communication link, a link confirmation frame sending unit, and a return link confirmation frame monitoring unit. The link confirmation frame sending unit causes the frame transfer processing unit to send a link confirmation frame for use in confirming a normal link status via the first communication link from the communication device to the counterpart communication device. The return link confirmation frame monitoring unit performs fault detection of the first and second communication links by monitoring a return link confirmation frame which is to be returned from the counterpart communication device to the communication device via the second communication link when the counterpart communication device receives the link confirmation frame via the first communication link.
    Type: Application
    Filed: October 11, 2011
    Publication date: February 2, 2012
    Inventors: Shinichi AKAHANE, Teruo Kaganoi, Tomohiko Kohno, Kazuo Sugai
  • Patent number: 8064353
    Abstract: The communication device has a frame transfer unit that executes frame transfer via the first communication link and the second communication link, a link confirmation frame sending unit, and a return link confirmation frame monitoring unit. The link confirmation frame sending unit causes the frame transfer processing unit to send a link confirmation frame for use in confirming a normal link status via the first communication link from the communication device to the counterpart communication device. The return link confirmation frame monitoring unit performs fault detection of the first and second communication links by monitoring a return link confirmation frame which is to be returned from the counterpart communication device to the communication device via the second communication link when the counterpart communication device receives the link confirmation frame via the first communication link.
    Type: Grant
    Filed: July 23, 2008
    Date of Patent: November 22, 2011
    Assignee: ALAXALA Networks Corporation
    Inventors: Shinichi Akahane, Teruo Kaganoi, Tomohiko Kohno, Kazuo Sugai
  • Publication number: 20110255534
    Abstract: A system having a plurality of network devices, each including: an interface module including a plurality of physical ports to transmit and receive packets; a computing module configured to execute a computing process with a computational expression using seed information, the seed information including at least one of destination information and source information associated with a received packet; a destination search module configured to, based on the result of the computation, select a physical port for transmission of the received packet from a plurality of candidate ports among the plurality of physical ports; and a modifying module configured to modify the computational expression, wherein the plurality of network devices include preceding-stage and subsequent-stage network devices, the subsequent-stage network device being directly coupled to the preceding-stage network device with physical wiring, and wherein the subsequent-stage and preceding-stage network devices are configured to use different exp
    Type: Application
    Filed: June 27, 2011
    Publication date: October 20, 2011
    Inventors: Hiroki YANO, Kazuo Sugai, Shinichi Akahane, Takao Nara
  • Publication number: 20110170270
    Abstract: The present invention relates to an electronic device including plural circuit board units that can be removed from the electronic device. The electronic device is designed to increase a data transfer rate between the circuit board units by using a circuit board for interconnect for electrically coupling the circuit board units placed in the electronic device, and using a cable for electrically or optically coupling the circuit board units placed in the electric device, or both of the cables.
    Type: Application
    Filed: January 12, 2011
    Publication date: July 14, 2011
    Inventors: MASAAKI Inoue, Takashi Matsumoto, Kazuhiro Matsuo, Junji Baba, Manabu Sawa, Kazuo Sugai
  • Patent number: 7969880
    Abstract: Computing process with a computational expression is executed using seed information including at least one of destination information and source information associated with a received packet. It is preferable to select a physical port for transmission of the received packet based on the result of the computation. It is also preferable to select a port group for transmission of the received packet based on the result of the computation. Here, the computational expression is capable of being modified. Meanwhile, the physical port for transmission of the received packet is selected from a plurality of candidate ports among the plurality of physical ports. The port group for transmission of the received packet is selected from among a plurality of port groups including a mutually different candidate port.
    Type: Grant
    Filed: July 31, 2007
    Date of Patent: June 28, 2011
    Assignee: ALAXALA Networks Corporation
    Inventors: Hiroki Yano, Kazuo Sugai, Shinichi Akahane, Takao Nara
  • Patent number: 7924833
    Abstract: The present invention relates to a packet transfer unit, which comprises a search key memory that stores a search key for a transfer destination of a packet and verification information generated from the search key, in association with a storage location of transfer information memorized in a transfer information memory, wherein a transfer information acquisition unit searches the search key memory by using the search key generated based on the header information and the verification information generated from the search key, acquires storage location information of the transfer information from the search key memory when a match with the search key and the verification information memorized in the search key memory is found, and acquires the transfer information stored in the transfer information memory based on the acquired storage location information, and wherein a transfer unit transfers the packet based on the acquired transfer information.
    Type: Grant
    Filed: April 6, 2009
    Date of Patent: April 12, 2011
    Assignee: Hitachi, Ltd.
    Inventors: Tatsuo Kanetake, Kazuo Sugai, Takashi Kumagai
  • Patent number: 7848321
    Abstract: The present invention is directed to rapidly replacing an output destination port with a bypass port and replacing packet output header information with bypass header information when a port accommodated by a router within an IP or MPLS network becomes faulty. The present invention provides a packet forwarding apparatus that accommodates two output ports. The packet forwarding apparatus is embodied in a structure having an element for storing the output information about each of a plurality of pieces of input header information, an element for storing the output information about an output port that is associated with input header information and used as a bypass in the event of a fault, and an output information address rewrite processor for writing, in the event of an output port failure, the output information address associated with an output port that should serve as a bypass.
    Type: Grant
    Filed: August 30, 2005
    Date of Patent: December 7, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Shinichi Akahane, Kazuo Sugai
  • Patent number: 7787442
    Abstract: A communication statistic information collection apparatus comprises a unit for searching a flow table for a flow entry corresponding to a searching key, a unit for collecting statistics information for each of flows, a unit for generating a packet for notifying a collector apparatus of stored statistics information, a unit for updating the flow table in accordance with statistics control information shown by a statistics control entry found as a result of searching the flow table, and a unit for generating a sample packet to be transferred to the collect or apparatus at a specified sampling rate in accordance with the statistics control information shown by a specified entry found from the flow table.
    Type: Grant
    Filed: February 3, 2005
    Date of Patent: August 31, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Shinichi Akahane, Mitsuru Nagasaka, Kazuo Sugai, Yuichi Ishikawa
  • Patent number: 7760632
    Abstract: Packets are relayed using a network relay device including a plurality of interface units. Each of the interface units includes one or more physical ports for connection to a line, and a bandwidth controller configured to control transmission bandwidth for packets received by the physical ports. Furthermore, a single specific physical port is selected as the output physical port from the distributed-control logical port based on output port group information unique to the output port group including the distributed-control logical port.
    Type: Grant
    Filed: July 31, 2007
    Date of Patent: July 20, 2010
    Assignee: Alaxala Networks Corporation
    Inventors: Hiroki Yano, Kazuo Sugai, Shinichi Akahane, Yoshinori Hachiya
  • Patent number: 7738465
    Abstract: A packet forwarding device equipped with a statistics collection device and statistics collection method for high speed ports at a low cost while maintaining the required statistical accuracy for each flow. In order to collect a statistic flow with the required accurate statistic information this device contains a high speed flow table, a flow table made up of many flow entries, a search decision table to decide whether to search the high speed flow table or large volume flow table; and the table to be searched is decided when a packet is received. The accuracy of the statistic information for the flow requiring accurate statistic information is guaranteed by the high speed flow table. Further by setting the large volume flow table and sampling rate as needed, statistic information for many flow entries can be collected with a sufficient flow of sampled statistic information, without lowering packet forwarding performance.
    Type: Grant
    Filed: July 7, 2004
    Date of Patent: June 15, 2010
    Assignee: Hitachi, Ltd.
    Inventors: Shinichi Akahane, Kazuo Sugai, Kazuaki Tsuchiya
  • Patent number: 7710962
    Abstract: The present invention provides a technology for processing packets, such as VoIP packets, with priority. A priority-designating unit designates priority information based on header information. A pointer searching unit refers to a pointer table to obtain pointer information corresponding to a destination address. A sorting unit sorts the pointer information into a high-priority queue and a low-priority queue according to the priority information. A next queue holds pointer information obtained from a destination information table. A scheduler extracts and outputs the pointer information from each queue in the following order of priority: the next queue, a high-priority queue, and a low-priority queue.
    Type: Grant
    Filed: March 24, 2006
    Date of Patent: May 4, 2010
    Assignee: Alaxala Networks Corporation
    Inventors: Yasuhiro Kodama, Kazuo Sugai, Shinichi Akahane, Hiroki Yano, Kaoru Okano, Naoya Kumita
  • Publication number: 20090196293
    Abstract: The present invention relates to a packet transfer unit, which comprises a search key memory that stores a search key for a transfer destination of a packet and verification information generated from the search key, in association with a storage location of transfer information memorized in a transfer information memory, wherein a transfer information acquisition unit searches the search key memory by using the search key generated based on the header information and the verification information generated from the search key, acquires storage location information of the transfer information from the search key memory when a match with the search key and the verification information memorized in the search key memory is found, and acquires the transfer information stored in the transfer information memory based on the acquired storage location information, and wherein a transfer unit transfers the packet based on the acquired transfer information.
    Type: Application
    Filed: April 6, 2009
    Publication date: August 6, 2009
    Inventors: Tatsuo Kanetake, Kazuo Sugai, Takashi Kumagai
  • Publication number: 20090141641
    Abstract: The communication device has a frame transfer unit that executes frame transfer via the first communication link and the second communication link, a link confirmation frame sending unit, and a return link confirmation frame monitoring unit. The link confirmation frame sending unit causes the frame transfer processing unit to send a link confirmation frame for use in confirming a normal link status via the first communication link from the communication device to the counterpart communication device. The return link confirmation frame monitoring unit performs fault detection of the first and second communication links by monitoring a return link confirmation frame which is to be returned from the counterpart communication device to the communication device via the second communication link when the counterpart communication device receives the link confirmation frame via the first communication link.
    Type: Application
    Filed: July 23, 2008
    Publication date: June 4, 2009
    Inventors: Shinichi Akahane, Teruo Kaganoi, Tomohiko Kohno, Kazuo Sugai
  • Patent number: 7522592
    Abstract: The present invention relates to a packet transfer unit, which comprises a search key memory that stores a search key for a transfer destination of a packet and verification information generated from the search key, in association with a storage location of transfer information memorized in a transfer information memory, wherein a transfer information acquisition unit searches the search key memory by using the search key generated based on the header information and the verification information generated from the search key, acquires storage location information of the transfer information from the search key memory when a match with the search key and the verification information memorized in the search key memory is found, and acquires the transfer information stored in the transfer information memory based on the acquired storage location information, and wherein a transfer unit transfers the packet based on the acquired transfer information.
    Type: Grant
    Filed: October 1, 2004
    Date of Patent: April 21, 2009
    Assignee: Hitachi, Ltd.
    Inventors: Tatsuo Kanetake, Kazuo Sugai, Takashi Kumagai
  • Publication number: 20090010262
    Abstract: A network routing apparatus in which packet forwarding units for performing a packet forwarding process are arranged in parallel to one another, a packet distribution unit for distributing packets to the packet forwarding units arranged in parallel to one another, a packet rearrangement unit for rearranging outputs of the packet forwarding units are provided in the network routing apparatus, and packet retrieving units for retrieving packet headers in the packet forwarding units are further arranged in parallel to one another.
    Type: Application
    Filed: September 2, 2008
    Publication date: January 8, 2009
    Inventors: Kazuo SUGAI, Nobuhito MATSUYAMA
  • Patent number: 7433301
    Abstract: A router in a backup path in an MPLS network adopting a label stack method aims to achieve the same quality-guarantee control as the one performed in a current path. In a packet transfer device accommodating first and second output lines, when the first line has a fault, upon a first packet being received, communication quality information in a header of the first packet is copied. A first header containing the copied priority information and a new label is added to the first packet, and the first packet is outputted to a second output line. When a second packet is received, communication quality information in a header of the second packet is copied, a second header containing the copied priority information and the new label is added to the second packet, and the second packet is outputted to the second output line.
    Type: Grant
    Filed: June 19, 2002
    Date of Patent: October 7, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Shinichi Akahane, Kazuo Sugai
  • Patent number: 7408935
    Abstract: A packet forwarding apparatus provided with a plurality of line interface units, comprises a routing processing unit for referring to a routing table, based on header information of received packet to specify one of output lines to output the received packet, a flow detection unit for referring to an entry table, in which a plurality of entries with flow conditions and control information are registered, to retrieve control information defined by the entry with a flow condition which coincides with that of the header information of the received packet, and a packet forwarding unit for transferring the received packet to one of the line interface units connected to the output line specified by the routing processing unit.
    Type: Grant
    Filed: May 3, 2004
    Date of Patent: August 5, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Takeki Yazaki, Takeshi Aimoto, Kazuo Sugai, Nobuhito Matsuyama
  • Patent number: 7397765
    Abstract: In one embodiment, a bandwidth monitoring device comprises a packet receiving circuit configured to receive packets; a counter configured to count a total packet length by adding up inputted packet lengths including a packet length of a next input packet and subtracting outputted packet lengths to produce a counted value; a timer configured to time a packet receiving time; a memory configured to store a number of packet receiving times and a number of counted values counted by the counter which correspond to the packet receiving times, respectively; a counter rate-of-change calculating portion configured to calculate a change rate by a first counted value corresponding to an oldest packet receiving time stored in the memory representing an oldest time at which a packet was received and a second counted value corresponding to a latest packet receiving time stored in the memory representing a latest time at which a packet was received; and a determining portion configured to decide whether the next input packet
    Type: Grant
    Filed: January 30, 2004
    Date of Patent: July 8, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Takeshi Aimoto, Nobuhito Matsuyama, Kazuo Sugai, Hiroki Yano, Yoshihiko Sakata, Shinichi Akahane, Yuichi Ishikawa
  • Publication number: 20080049778
    Abstract: Packets are relayed using a network relay device including a plurality of interface units. Each of the interface units includes one or more physical ports for connection to a line, and a bandwidth controller configured to control transmission bandwidth for packets received by the physical ports. Furthermore, a single specific physical port is selected as the output physical port from the distributed-control logical port based on output port group information unique to the output port group including the distributed-control logical port.
    Type: Application
    Filed: July 31, 2007
    Publication date: February 28, 2008
    Inventors: Hiroki Yano, Kazuo Sugai, Shinichi Akahane, Yoshinori Hachiya
  • Publication number: 20080037544
    Abstract: Computing process with a computational expression is executed using seed information including at least one of destination information and source information associated with a received packet. It is preferable to select a physical port for transmission of the received packet based on the result of the computation. It is also preferable to select a port group for transmission of the received packet based on the result of the computation. Here, the computational expression is capable of being modified. Meanwhile, the physical port for transmission of the received packet is selected from a plurality of candidate ports among the plurality of physical ports. The port group for transmission of the received packet is selected from among a plurality of port groups including a mutually different candidate port.
    Type: Application
    Filed: July 31, 2007
    Publication date: February 14, 2008
    Inventors: Hiroki YANO, Kazuo SUGAI, Shinichi AKAHANE, Takao NARA