Abstract: A method of reserving a transmission band of a transmission line for transmitting data via a plurality of Internet service providers on the Internet between first and second communication devices includes the steps of (a) the first communication device requesting an intermediary server to reserve the transmission band and (b) the intermediary server reserving the transmission band for the first and second communication devices.

Abstract: A method of transferring data in a connection-type network in which nodes are connected via communication lines and terminals are connected to the nodes includes the steps of sending a request from a first one of the terminals to a second one of the terminals via a connection established on a first communication line, the request requesting transfer of data from the second one of the terminals to the first one of the terminals via a second communication line, establishing a connection on the second communication line between a first one of the nodes having the first one of the terminals attached thereto and a second one of the nodes having the second one of the terminals attached thereto, and transferring all or part of the data via the connection on the second communication line, wherein the second communication line is established to be in existence for a predetermined duration of time or for a time period during which all or part of the data is transferred.

Abstract: Disclosed is a router network which, regardless of the format used for a network, ensures that communication with another segment will be maintained, even though a fault may occur at a router. The router network includes a plurality of local area networks (LANs), furnished with routers for independent communication; wherein the plurality of local area networks communicate with each other using the Internet protocol (IP) or the Internet work packet protocol (IPX); wherein a network environment for a subordinate segment serviced by a specific router is established for a different router; and wherein when a fault occurs at the specific router, the different router is used as a proxy router to provide communication support for the subordinate segment of the specific router in accordance with the network environment which was set in advance.

Abstract: A method of reserving a transmission band of a transmission line for transmitting data via a plurality of Internet service providers on the Internet between first and second communication devices includes the steps of (a) the first communication device requesting an intermediary server to reserve the transmission band and (b) the intermediary server reserving the transmission band for the first and second communication devices.

Abstract: A plurality of datagram VCCs, each of which is exclusively for connectionless transfer of data, are established between mutually adjacent exchanges in advance, one of these datagram VCCs is assigned exclusively for connectionless data communication and connectionless communication is performed using this datagram VCC. Specifically, an originating terminal disassembles connectionless data into data cells, inserts a cell (a leading cell), which indicates the destination address of a terminal that is the destination of the data, at the head of the data cells and then sends the leading cell to the exchange prior to the data cells. The exchange assigns a prescribed datagram VCC for connectionless communication upon referring to the destination terminal address indicated by the leading cell and thenceforth uses this VCC to transmit data cells having line identifier identical with that of the leading cell.

Abstract: A local area network (LAN) connection method runs an existing LAN application in an asynchronous transfer mode (ATM) network to connect LANS. The LAN connection method includes the steps of (a) in a LAN emulation (LANE) protocol which operates an existing network in the ATM network, connecting LAN emulation servers (LESs) which mainly cope with addresses from medial access control (MAC) addresses to ATM addresses in emulated LANs (ELANs) by a virtual channel connection (VCC) for transferring a LAN emulation address resolution protocol (LE ARP) which inquires the ATM address from the MAC address, and (b) transferring a LE ARP request with respect to a LAN emulation client (LEC) in a second ELAN to a LES in the second ELAN when a LES in a first ELAN receives the LE ARP request from a LEC in the first ELAN.

Abstract: In a switching hub capable of realizing a high-speed LAN communication, this switching hub is equipped with a switch unit and a plurality of ports connected to this switch unit. When a frame is received from a terminal, each of these ports attaches a tag to which a transmission source LAN number has been set to this received frame, and thereafter supplies the frame with this tag to the switch unit. When the frame with tag is received from another port within another switching hub, the port directly supplies this frame with tag to the switch unit. The switch unit registers the transmission source LAN number of the supplied frame, a transmission source MAC address, and an input port number into a LAN table. While such a port for supplying a frame is determined, either a transmission source address of this frame or a transmission source LAN number thereof is used as a retrieve key so as to try to read out the port number from the LAN table.