Patents by Inventor Ryouichi Mutoh

Ryouichi Mutoh 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).

  • Patent number: 7496055
    Abstract: A layer 2 loop detection apparatus includes a unit recognizing a topology of an L2 network at normal time by collecting MIB information including information concerning ports of a plurality of L2 switches from the plurality of L2 switches through SNMP communication; a unit discriminating, based on a topology recognition processing, a blocking port for traffic blocking and a disable port under a port disable state each set under a Spanning Tree Protocol (STP); a unit setting each of the blocking port and the disable port as a monitoring point and periodically monitoring a state thereof; and a unit performing detection of an L2 loop by re-collecting a part of the MIB information from the plurality of L2 switches through SNMP communication and re-recognizing the topology of the L2 network, the detection of the L2 loop detection being triggered by a change of a state of one of the blocking port and the disable port.
    Type: Grant
    Filed: September 30, 2004
    Date of Patent: February 24, 2009
    Assignee: Fujitsu Limited
    Inventors: Kiichi Sugitani, Ryouichi Mutoh, Tetsuya Nishi
  • Publication number: 20050220036
    Abstract: A layer 2 loop detection apparatus includes a unit recognizing a topology of an L2 network at normal time by collecting MIB information including information concerning ports of a plurality of L2 switches from the plurality of L2 switches through SNMP communication; a unit discriminating, based on a topology recognition processing, a blocking port for traffic blocking and a disable port under a port disable state each set under a Spanning Tree Protocol (STP); a unit setting each of the blocking port and the disable port as a monitoring point and periodically monitoring a state thereof; and a unit performing detection of an L2 loop by re-collecting a part of the MIB information from the plurality of L2 switches through SNMP communication and re-recognizing the topology of the L2 network, the detection of the L2 loop detection being triggered by a change of a state of one of the blocking port and the disable port.
    Type: Application
    Filed: September 30, 2004
    Publication date: October 6, 2005
    Inventors: Kiichi Sugitani, Ryouichi Mutoh, Tetsuya Nishi