Abstract: A communication system includes an information processing device and a relay device. The relay device stores information identifying a transfer destination device that is a transfer destination of a packet that includes data destined for the information processing device, and relays communication between a first network that includes the transfer destination device and a second network. When the relay device receives, from a transmission source in the second network, a first data packet that includes the data destined for the information processing device, the relay device generates a device index value that is used when the relay device determines the transmission source from among devices included in the second network. The relay device transmits, to the transfer destination device, a second data packet obtained by adding, to the first data packet, the device index value and a network index value that identifies the second network.

Abstract: A selection device is selected from a first group in a first cluster. The node devices of the first group can communicate with a node device in a second cluster adjacent to the first cluster. The selection device performs transmission and reception of a report frame that reports an identifier of a node device included in the first group. The selection device selects from the first group a first relay device that relays a relay frame used for a communication between a node device in the first cluster and a node device in the second cluster. The first relay device determines anode device adjacent to the first relay device to be a second relay device that relays the relay frame to a node device in the second cluster.

Abstract: A communication control method to be executed by a communication device, includes: transmitting, to one or more communication devices coupled to the communication device, a packet in which a destination is set; and determining, based on the number of paths that are among paths extending through the one or more communication devices to the destination and through which a response to the packet is received from the destination, the number of times of retransmission in the transmission of another packet to the destination.

Abstract: A communication system includes an information processing device and a relay device. The relay device stores information identifying a transfer destination device that is a transfer destination of a packet that includes data destined for the information processing device, and relays communication between a first network that includes the transfer destination device and a second network. When the relay device receives, from a transmission source in the second network, a first data packet that includes the data destined for the information processing device, the relay device generates a device index value that is used when the relay device determines the transmission source from among devices included in the second network. The relay device transmits, to the transfer destination device, a second data packet obtained by adding, to the first data packet, the device index value and a network index value that identifies the second network.

Abstract: A node apparatus includes a TTL memory configured to store a TTL value for a first node apparatus in the cluster; a receiving unit configured to receive a first Hello packet including a first sequence number and a second Hello packet including a second sequence number that is incremented when the node apparatus transmits a Hello packet; a sequence number judging unit configured to judge whether a first sequence number and a second sequence number match each other; a TTL decrementing unit configured to perform a process to decrement the TTL value stored in the TTL memory, when the first sequence number and the second sequence number are identical according to a judgment; and a cluster information updating unit configured to separate the first node apparatus from the cluster, when the TTL value for the first node apparatus becomes equal to or smaller than a prescribed value.

Abstract: A node apparatus in a network including a plurality of node apparatuses includes: a cluster information memory configured to store apparatus identification information of node apparatus included in a first cluster including the node apparatus; a merge cluster node number determination unit configured to obtain the number of node apparatuses included in the second cluster based on information included in the hello packet upon receipt of a hello packet from one of adjacent node apparatuses included in a second cluster, and to determine whether a sum of the number of node apparatuses included in the first cluster and that of node apparatuses included in the second cluster is equal to or smaller than a maximum number of cluster nodes; and a cluster merge processing unit configured to merge the second cluster with the first cluster based on a result of the determination.

Abstract: A node device includes a transmitter, processor, and a receiver. The receiver receives a packet from an adjacent node device. The processor generates a cluster list and a first hello packet. The cluster list records device identification information of a node device included in a cluster. The cluster is a group of node devices for which route information is stored. The first hello packet reports the route information with cluster identification information of the cluster. The transmitter broadcasts the first hello packet. Upon receipt of, from a free-node device that does not belong to a cluster, a second hello packet that includes information that associates the cluster identification information with device identification information of the free-node device, the processor adds the device identification information of the free-node device to the cluster list until a number of node devices recorded in the cluster list reaches a threshold.

Abstract: A node receives, from a neighboring node that is a node in the neighborhood, neighboring node information indicating a node that neighbors the neighboring node and determines whether a common neighboring node is present, the common neighboring node being common amongst a neighboring node and a node indicated by the received neighboring node information. When it is determined that the common neighboring node is present, the node registers, in a storage unit, information that a link on a simplex path is to be formed with the common neighboring node or the neighboring node that is the source of the neighboring node information. Alternatively, when it is determined that the common neighboring node is not present, the node registers, in the storage unit, information that a link on a duplex path is to be formed with the neighboring node that is the source of the neighboring node information.

Abstract: A selection device is selected from a first group in a first cluster. The node devices of the first group can communicate with a node device in a second cluster adjacent to the first cluster. The selection device performs transmission and reception of a report frame that reports an identifier of a node device included in the first group. The selection device selects from the first group a first relay device that relays a relay frame used for a communication between a node device in the first cluster and a node device in the second cluster. The first relay device determines anode device adjacent to the first relay device to be a second relay device that relays the relay frame to a node device in the second cluster.

Abstract: A node transmits a route search demand, which is a demand to search for a route from the node to a predetermined device among adjacent communication devices, to an adjacent communication device that is not selected as a transmission destination of the route search demand. The node transmits the route search demand when the number of adjacent communication devices serving as confirmed routes is smaller than a predetermined number and when there is an adjacent communication device that has not been selected. The node stops transmission of the route search demand when the number of the adjacent communication devices serving as the confirmed routes reaches the predetermined number. The node transmits a warning to the predetermined device when the number of the adjacent communication devices serving as the confirmed routes is smaller than the predetermined number and when there is no adjacent communication device that has not been selected.

Abstract: A communication control method to be executed by a communication device, includes: transmitting, to one or more communication devices coupled to the communication device, a packet in which a destination is set; and determining, based on the number of paths that are among paths extending through the one or more communication devices to the destination and through which a response to the packet is received from the destination, the number of times of retransmission in the transmission of another packet to the destination.

Abstract: A node apparatus in a network including a plurality of node apparatuses includes: a cluster information memory configured to store apparatus identification information of node apparatus included in a first cluster including the node apparatus; a merge cluster node number determination unit configured to obtain the number of node apparatuses included in the second cluster based on information included in the hello packet upon receipt of a hello packet from one of adjacent node apparatuses included in a second cluster, and to determine whether a sum of the number of node apparatuses included in the first cluster and that of node apparatuses included in the second cluster is equal to or smaller than a maximum number of cluster nodes; and a cluster merge processing unit configured to merge the second cluster with the first cluster based on a result of the determination.

Abstract: A node apparatus includes a TTL memory configured to store a TTL value for a first node apparatus in the cluster; a receiving unit configured to receive a first Hello packet including a first sequence number and a second Hello packet including a second sequence number that is incremented when the node apparatus transmits a Hello packet; a sequence number judging unit configured to judge whether a first sequence number and a second sequence number match each other; a TTL decrementing unit configured to perform a process to decrement the TTL value stored in the TTL memory, when the first sequence number and the second sequence number are identical according to a judgment; and a cluster information updating unit configured to separate the first node apparatus from the cluster, when the TTL value for the first node apparatus becomes equal to or smaller than a prescribed value.

Abstract: A computer-readable recording medium has stored therein a program for causing a computer to execute a process including storing, as a variable set, a database of a variable that associates a key, a value and a synchronization destination corresponding to the key, executing a process of requesting that the variable in the variable set of the computer be referred to or updated in a state and evaluating a condition so as to make the state transition to a different state, and communicating the key specified by the request with the synchronization destination for the variable corresponding to the key specified by the request and synchronizing the value of the variable corresponding to the key in the computer and the value of the variable corresponding to the key in the variable set of the synchronization destination when the process of requesting is executed.

Abstract: A service search method, judges when receiving a service search request from a service search requester whether or not a local server matches a service search condition stored in the service search request by referring to the attribute about the local server; selects according to the route information a server having no search record in the search history information which is added to the service search request when it is judged that the local server does not match the service search condition, and transfers to the selected server the service search request to which the information about the local server is added as the search history information; and notifies the service search requester of a search request reply according to the route information generated by the local server when it is judged that the local server matches the service search condition.

Abstract: A node device includes a transmitter, processor, and a receiver. The receiver receives a packet from an adjacent node device. The processor generates a cluster list and a first hello packet. The cluster list records device identification information of a node device included in a cluster. The cluster is a group of node devices for which route information is stored. The first hello packet reports the route information with cluster identification information of the cluster. The transmitter broadcasts the first hello packet. Upon receipt of, from a free-node device that does not belong to a cluster, a second hello packet that includes information that associates the cluster identification information with device identification information of the free-node device, the processor adds the device identification information of the free-node device to the cluster list until a number of node devices recorded in the cluster list reaches a threshold.

Abstract: Anode device includes a receiver, a processor, memory, and a transmitter. The receiver receives a path information packet for notification of path information about a network. The processor generates a participation request packet for requesting a first node device selected between an adjacent node device and a node device communicable through the adjacent node device to participate in a first local cluster. The memory stores a path to each affiliated node device affiliated with the first cluster. The transmitter transmits the participation request packet to the first node device. When a number of affiliated node devices which are affiliated with the first cluster exceeds a threshold, the processor generates a generation request packet for requesting a second node device which is not affiliated with the first cluster to generate a second cluster different from the first cluster. The transmitter transmits the generation request packet to the second node device.

Abstract: A gateway apparatus includes a sorting destination storing unit which stores information of a sorting destination that performs a process according to a destination, a sorting unit which outputs an input destination and transmission data to a sorting destination according to the destination searched from information stored in the sorting destination storing unit, a transmission destination storing unit which stores information of a transmission destination for each destination, an input/output unit which performs a transmission process and a reception process according to a corresponding protocol stack, and a protocol converting unit which assembles, when a destination and transmission data are input from the sorting unit, the destination and the transmission data as data that matches a format of a corresponding protocol stack, and instructs the input/output unit of a corresponding protocol stack to transmit the assembled data to a transmission destination according to the destination.

Abstract: A node transmits a route search demand, which is a demand to search for a route from the node to a predetermined device among adjacent communication devices, to an adjacent communication device that is not selected as a transmission destination of the route search demand. The node transmits the route search demand when the number of adjacent communication devices serving as confirmed routes is smaller than a predetermined number and when there is an adjacent communication device that has not been selected. The node stops transmission of the route search demand when the number of the adjacent communication devices serving as the confirmed routes reaches the predetermined number. The node transmits a warning to the predetermined device when the number of the adjacent communication devices serving as the confirmed routes is smaller than the predetermined number and when there is no adjacent communication device that has not been selected.

Abstract: A node receives, from a neighboring node that is a node in the neighborhood, neighboring node information indicating a node that neighbors the neighboring node and determines whether a common neighboring node is present, the common neighboring node being common amongst a neighboring node and a node indicated by the received neighboring node information. When it is determined that the common neighboring node is present, the node registers, in a storage unit, information that a link on a simplex path is to be formed with the common neighboring node or the neighboring node that is the source of the neighboring node information. Alternatively, when it is determined that the common neighboring node is not present, the node registers, in the storage unit, information that a link on a duplex path is to be formed with the neighboring node that is the source of the neighboring node information.