Abstract: A power line communication apparatus controls a transmission using a plurality of parameters. The power line communication apparatus includes: a registration processor which performs a registration process for achieving a state to be communicable with another power line communication apparatus through a power line by use of transmission data based on a first parameter set at a first value and a second parameter set at a second value, a parameter controller which changes the first parameter to the third value to lengthen a communicable distance and the second parameter to the fourth value to shorten the communicable distance when the registration process has ended in failure. When the registration process has ended in failure, the registration processor retry the registration process by use of transmission data based on the first parameter set at a third value and the second parameter set at a fourth value.

Abstract: A communication apparatus which transmits data to another communication apparatus through a transmission channel, includes: a display which displays a plurality of communication rates; and a controller which permits the display to display the communication rates. The controller acquires a first communication rate received from the another communication apparatus and based on a predetermined signal transmitted to the another communication apparatus through the transmission channel at a first time. The controller acquires a second communication rate received from the another communication apparatus and based on a predetermined signal transmitted to the another communication apparatus through the transmission channel at a second time. The controller calculates a plurality of communication rates on the basis of the first and second communication rate.

Abstract: An IP device (for example, network cameras 3a, 3b, and 3c) connectable to a router (for example, a router 2) makes a request to the router for assignment of a port number when a predetermined operation is performed, and notifies a management server 6 connected to a wide area network of address data containing an assigned port number when the port number is assigned from the router, wherein address data containing the port number can be registered in the management server 6 on the wide area network, so that, even when access is made from the terminal 4 on the wide area network side with a port number that is locally updated, access is made possible by transmitting address data of the IP device to the terminal 4.

Abstract: The present invention provides a repeater which automatically closes a dynamically opened port in accordance with prior setting, the repeater including: a port mapping table where a global IP address and an external port number, or an external port number on the Internet is associated with a local IP address and an internal port number of a terminal connected to a LAN; a control unit which, receiving a communications packet to which an external port number is specified, converts the external port number to an internal port number based on the port mapping table and transfers the internal port number to the LAN; a timer unit which counts the unoccupied time of the port after transferring a communications packet to which an external port number is specified; and a port management unit which checks whether the registered machine is present on the LAN and in case it is absent, deletes registration concerning the external port number from the port mapping table.

Abstract: A power line communication apparatus transmits a signal to a first power line communication apparatus through a power line connecting to a second power line communication apparatus. The power line communication apparatus includes an information retriever for retrieving transmission rate information indicating both a first transmission rate and second transmission rate. The first transmission rate correspond to a first path of the power line along which the signal is directly transmitted to the first power line communication apparatus, and the second transmission rate corresponds to a second path of the power line along which the signal is transmitted through the second power line communication apparatus to the first power line communication apparatus. A selector selects, based on the transmission rate information, a path corresponding to a higher transmission rate among the first and second paths. A transmitter transmits the signal through the selected path.

Abstract: A representative registration apparatus 100 includes: a master and slave apparatus supporting control section 101 which generates, according to a registration message received from a master apparatus or a slave apparatus, a registration message to be transmitted to the master apparatus or the slave apparatus; a communication range switching section 104 for switching a transmission range of a message to be transmitted; and a communication range determining section 107 which determines, according to a destination of a registration message generated by the master and slave apparatus supporting control section 101, a transmission range of the registration message thus generated, so as to provide instructions to the communication range switching section 104.

Abstract: A communication apparatus has a electrical outlet that is electrically connected to a power connector so as to supply power externally; a connection detector that detects connection of an external plug to the electrical outlet; and a controller that uses a receiver and a transmitter so as to perform setting with a device connected to the electrical outlet, when external connection is detected at the electrical outlet.

Abstract: PLC modems and a PLC communication system that includes the PLC modems receive a multicast packet from a video server of a multicast group. When a MAC address table is set therein, the PLC modems and the PLC communication system convert the multicast packet into a unicast packet and transmit the converted packet to a power line. When no MAC address is set, the PLC modems and the PLC communication system transmit the multicast packet to the power line.

Abstract: An IP device (for example, network cameras 3a, 3b, and 3c) connectable to a router (for example, a router 2) makes a request to the router for assignment of a port number when a predetermined operation is performed, and notifies a management server 6 connected to a wide area network of address data containing an assigned port number when the port number is assigned from the router, wherein address data containing the port number can be registered in the management server 6 on the wide area network, so that, even when access is made from the terminal 4 on the wide area network side with a port number that is locally updated, access is made possible by transmitting address data of the IP device to the terminal 4.

Abstract: The present invention has an object to provide a relay device capable of performing dynamic port forward setting to open a port even if performing a connection in two stages and being connected to a network and a port forward setting method, and relates to a router for relaying a data packet which has such a structure as to comprise a control portion for giving a port forward setting request to an upper router 2 to perform the port forward setting of the upper router 2 and to relate port forward setting for a CP4 to port forward setting of a router upon receipt of the port forward setting request from the CP4 when a WAN side I/F portion is connected to an internet 1 through the upper router 2 and a LAN side I/F portion is connected to the CP4.

Abstract: The invention aims at providing a server which manages address information for servers subordinate to a port-forwarding relay device (router) thus allowing an access from a wide area network. A representative server issues a request to assign a default port number to a router. The port management unit of the representative server registered to a default port number acquires the IP address of the router (wide area network address) and port mapping information (port number information on other equipment) from the router and retains the information acquired. In case it is determined that an access from the wide area network is first directed to a representative server, the representative server displays in a list the port number information on the accessing terminal in response to an access from the wide area network. This allows an external user to readily access desired equipment. The representative server periodically makes a port mapping information to the router and updates the information.

Abstract: A wireless apparatus capable of being communicated to a plurality of terminal apparatus by a wireless manner, is comprised of: a wire interface for being communicated to the terminal apparatus by a wire manner; and control means for controlling a setting mode in which when the control means receives a transmit packet from the terminal apparatus connected to the wire interface and the transmit packet contains an address specific to the terminal apparatus, wireless setting information and/or network setting information are transmitted with respect to the terminal apparatus of the specific address. A wireless apparatus and a wireless terminal apparatus can be provided, which are known as a router apparatus, which are capable of easily setting a wireless unit such as SSID and an encryption system, and also capable of readily setting a network which contains the setting operation of the wireless unit.

Abstract: The present invention provides a repeater which automatically closes a dynamically opened port in accordance with prior setting, the repeater including: a port mapping table where a global IP address and an external port number, or an external port number on the Internet is associated with a local IP address and an internal port number of a terminal connected to a LAN; a control unit which, receiving a communications packet to which an external port number is specified, converts the external port number to an internal port number based on the port mapping table and transfers the internal port number to the LAN; a timer unit which counts the unoccupied time of the port after transferring a communications packet to which an external port number is specified; and a port management unit which checks whether the registered machine is present on the LAN and in case it is absent, deletes registration concerning the external port number from the port mapping table.