Abstract: When a partial rate guaranteed service is applied to a communication line connecting predetermined routers, a TCP tunnel (TCP connection) is established between the routers, a packet whose destination is a router connected to the communication line is passed through the TCP tunnel, and other packets of an application using a UDP of a VoIP or the like are forwarded by a normal routing control without being passed through the TCP tunnel.

Abstract: A route controlling apparatus is provided on a center side in a network having a carrier-redundant configuration in which the center side and a base side are connected using a plurality of different carriers, and includes a load distribution table that stores information for load distribution; and a controlling unit that creates, when data is received by a host on the center side from a host on the base side, a new entry in the load distribution table. In the new entry, a carrier selected for transmission of the data by a router on the base side is associated with an address of the host on the base side. The controlling unit refers to the entry to select the carrier as a route when data is to be transmitted from the host on the center side to the host on the base side.

Abstract: A route controlling apparatus is provided on a center side in a network having a carrier-redundant configuration in which the center side and a base side are connected using a plurality of different carriers, and includes a load distribution table that stores information for load distribution; and a controlling unit that creates, when data is received by a host on the center side from a host on the base side, a new entry in the load distribution table. In the new entry, a carrier selected for transmission of the data by a router on the base side is associated with an address of the host on the base side. The controlling unit refers to the entry to select the carrier as a route when data is to be transmitted from the host on the center side to the host on the base side.

Abstract: A packet transfer apparatus switches and transfers cell or frame signals. The apparatus efficiently routes cell or frame signals that are made from packet data based on Internet protocols. The apparatus has a switch for making a connection path among a first node, a second node, and a routing device, a memory for storing outgoing route data, and a shortcut controller.

Abstract: When a partial rate guaranteed service is applied to a communication line connecting predetermined routers, a TCP tunnel (TCP connection) is established between the routers, a packet whose destination is a router connected to the communication line is passed through the TCP tunnel, and other packets of an application using a UDP of a VoIP or the like are forwarded by a normal routing control without being passed through the TCP tunnel.

Abstract: A Layer 2 switching device is provided, which includes: a flow table in which an entry is registered, the entry including an IP address of one host selected from first and second hosts as a source IP address thereof and MAC and IP addresses of the other host as MAC and destination IP addresses thereof; a converter that, in the case where data having the IP address of the one host set as the source IP address thereof and having the IP address of the other host set as the destination IP address thereof is received from the one host, converts the destination MAC address set in the data into the MAC address of the other host based on the entry in the flow table; and a unit that sends out the data, which has the destination MAC address converted, to the other host.

Abstract: “A System, Method, and Device for Facillitating Multi-Path Cryptographic Communication” A system, method, and node device for cryptographic communication are disclosed. Cryptographic tunnels between a source and destination node having intermediate stops at one or more repeating nodes are used to send and receive encrypted packets. This method of cryptographic communication is the default route of message exchange and allows repeating nodes to decrypt and re-encrypt packets along the route. When cryptographic communication traffic at a repeating node exceeds or falls below a certain threshold value, a direct route cryptographic tunnel is established between a source and destination pair of nodes, thereby diminishing encryption and decryption process load at intermediate repeating nodes.

Abstract: A looping detection apparatus used in a frame-relay communications system and capable of detecting looping without fail through confirmation of link completeness according to a two-way PVC status confirmation procedure. A status enquiry message transmitting unit transmits a status enquiry message with a first identification code carried at a predetermined position of a signal by means of which the status enquiry message is transmitted. On receiving the status enquiry message, a status response message returning unit creates a status response message based on the status enquiry message and sends the status response message back to a first node with a second identification code carried at the predetermined position.

Abstract: The present invention relates to a data exchange and a data exchanging method each suitable for a communication system which tends to be congested due to high-speed communication such as a frame relay network. The data exchange that accommodates plural data terminals via terminal trunks includes a congestion status detecting unit for detecting the congestion status in a standard transit trunk, and the transit trunk control unit including a first alternate control unit that controls to transfer data to be transferred by a roundabout route using a backup transit trunk, based on detection information from the congestion status detecting unit. The purpose of the present invention is to suppress the occurrence of congestion or the frame disposal of a frame at a congestion occurrence time.

Abstract: A frame relay switching apparatus in a frame relay network employs a frame format used in a frame relay communication between a plurality of terminals, performed by identifying a destination by a data link connection identifier (DLCI) in an address field. Priority or non-priority information for an identifier provided in a frame being transmitted for identifying a destination terminal is registered for each DLCI so that a zone assigned to each of them is not overflown, to prevent a frame having a priority DLCI from being discarded. In case of congestion, all frames having identical non-priority DLCIs are discarded at the same time. The switching apparatus includes a plurality of transmitting buffers provided at each outgoing line, and a common buffer, which can be shared by a plurality of lines. A congested line writes a received frame in the common buffer and takes the frame out from the common buffer to write it in a respective transmitting buffer when the congestion has been resolved.

Abstract: Data flow control applied to a packet communication system including data terminal equipment (DTE), a first MODEM connected to one of the DTEs, a telephone switching nework (TSN) connected to the first MODEM, a packet switching network (PSN) having an assembly and disassembly equipment (PAD) and a second MODEM connected to PAD and provided between PAD and TSN and carried out by using MODEM control signals, logic signal "1" and "0", and control characters, DC1 and DC3, is performed: discriminating a designated response signal, /REL in CONNECT .alpha..beta..gamma..delta./REL. from a header of data transferred through the first and second MODEMs each having a buffer memory used for error correction of the data. In addition the MODEM control signals are made effective and the control characters are made ineffective and are controlled when the designated response signal is detected.

Abstract: A modem is connected to a terminal equipment and couples to another modem via a transmission line. The modem includes a data transmission and reception part for making data transmission and reception with the terminal equipment, and a modem part for determining a modulation technique, for modulating a transmission signal from the other modem. In addition, the modem includes a data compression and decompression part for determining a compression technique. The compression technique is used for compressing serial data from the data transmission and reception part before supplying the same to the modem part and for decompressing the compressed serial data from the modem part before supplying the same to the data transmission and reception part.