Abstract: In the case that a plurality of nodes determines a transmission speed prior to point-to-point communication, in order for minimizing a throughput difference between a node with a high transmission speed determined and a node with a low transmission speed determined, the transmission speed recording section 11 of a slave node 1 records a best transmission speed (a maximum transmission speed) for the slave node 1, the transmission speed setting section 12 determines the transmission speed upon negotiation with the master node when starting data transmission, the transmission speed setting section 12 sets a control transmission speed which is the same as or lower than a determined transmission speed based upon the maximum transmission speed and the determined transmission speed. The transmission speed controlling section 13 controls the transmission speed by using a buffer storage 14 so as not to exceed the control transmission speed set by the transmission speed setting section 12.

Abstract: A vehicle-control communication system, in which a plurality of control function units such as ECI (engine control) are separated into an I/O processing function and an operation control function, and the I/O processing function for each control function unit comprises I/O processing nodes, while the operation control function is formed as one of the operation control nodes for each of vehicle control groups each obtained by integrating control function units with a relation therebetween into one group. Transmit-receive of information within each of the vehicle control groups is executed via any of first communication lines, while transmit-receive of information between the vehicle control groups is executed via a second communication line.

Abstract: An encryption apparatus enables encrypted communications using existing network equipment which does not have an encryption function, such as a server, a client, or a router. The encryption apparatus is connected to a section between a terminal and a network, data from the terminal is encrypted and sent to the network, data from the network is decrypted and sent to the terminal, and a connection control frame between the terminal and the network is not encrypted.

Abstract: A protocol processing apparatus is presented having a plurality of CPUs for processing communication protocol data in parallel so as to achieve a high measure of efficiency. The apparatus provides a common memory including a CPU state table that is accessible by the plurality of CPUs. The CPU state table associates an idle flag, a remote node identifier, and a process start time with each of the plurality of CPUs. At least one line interface selects a CPU from the plurality of CPUs according to the contents of the CPU state table, selecting an idle CPU if one is available, selecting a CPU with the oldest process start time if no idle CPU is available, or selecting a busy CPU if the communication data to be processed is related to communication data already running on the busy CPU.

Abstract: A transmitting-receiving unit or a set of upper rank transmitting-receiving units and lower rank transmitting-receiving units are provided, and one or a plurality of circuits selected by a circuit selective switch unit from among many circuits are connected to the transmitting-receiving unit or the set. As a result, the burden of the control unit provided in the communication device is reduced. The maintenance of a route table which is used in transmitting packets from the highest rank station to the lowest rank station via other communication devices is made unnecessary by transferring the route table in order from the highest rank stations to the lowest rank stations.