Abstract: A communication control apparatus includes an input and output unit responsive to reception of a packet, for generating a search request and a destination address of the packet to receive a resultant route data, and for transmitting the packet based on the resultant route data. A memory stores a route tree table having a tree structure of a plurality of nodes, each of which has a node data. A route searching circuit refers to the route tree table in response to the search request to determine a route data of a final node data as the resultant route data from the destination address, and outputs the resultant route to the input and output unit.

Abstract: A communication quality control system for deciding an optimum communication quality in a received datagram to transfer the datagram, in which not only a destination is decided according to the data of the protocol layer 3 and beneath included in the datagram, but also attribute information of communication is taken out by an attribute detecting unit, according to the information of the respective protocol layers 4, 5, 6, and 7 or one of them, and communication quality for sending the datagram is decided by a communication quality deciding unit and a connection communication quality control unit, according to the quality information of connection corresponding to the attribute information taken out.

Abstract: In a communications network formed by routers interconnected by parallel component links, hello packets are exchanged between neighbor routers at intervals to know each other in a learning process and update their status. Each router groups the parallel component links into a bundled link according to a link-up or link-down request and produces a first database mapping the relationships between component links and bundled links. The router performs routing calculations according to a link state routing algorithm using the bundled link as a unit of transmission medium and produces a second database mapping relationships between destination addresses and bundled links. The first and second databases are downloaded to interface units connected to the parallel component links. When a data packet is received, the databases are used for translating the header of the data packet for allowing it to be routed through a switch for transmission.

Abstract: A multi-layer class identifying communication apparatus, includes an input interface connected to input communication lines; a switch circuit; and an output interface connected to output communication lines. The input interface comprises an allocating section which determines a class identifier indicative of one of classes to which an IP packet belongs, from header data of the IP packet received through one of the input communication lines, and allocates an IP-QOS (Internet-Protocol-Quality-of-Service) code to the IP packet. The switch circuit selects one of the output communication lines based on a destination address of the IP packet, such that the IP packet is outputted from the output interface to the selected output communication output interface.

Abstract: A datagram relaying apparatus includes a plurality of protocol terminating units, and a destination determining processor. The destination determining processor includes a path selecting section which determines a transfer destination route for a stream of packets received from any of the protocol terminating units. The path selecting section determines whether or not transfer of the received stream of packets to the transfer destination route is in an inhibition state, and selects another transfer destination route when the transfer of the packet to the transfer destination route is in the inhibition state.