Abstract: In an input cell policing method in a network of an asynchronous transfer mode, according to information contained in a header field of each input cell, a group to which the cell belongs is identified. For each group, there are set a plurality of time frames having a predetermined length and mutually different phases to count the number of input cells in each time frame period. For each time frame, the count value of input cells is compared with a predetermined threshold value. An input cell for which the count value exceeds the threshold value in either one of the time frames is assumed to be an excess cell. The excess cell is discarded or a violation mark is added thereto.

Abstract: Distributed LANs are connected to a wide area network through terminal adapters, which are interconnected by virtual circuits to form a logical bus network. Each terminal adapter copies cells received through the virtual circuit that is allocated for multicasting, and transfers the copied cells to the adjacent terminal adapters via preset virtual circuits. The terminal adapters assemble a part or all of the transmitted message from the received cells and, according to the contents of the assembled message, transfer the copies of the cells to the adjacent terminal adapters through predetermined virtual circuits.

Abstract: In a packet communication network in which a plurality of subscriber's lines are connected with a packet switching unit via a multiplexer and each of terminal units declares the packet rate on call request, a packet rate monitoring circuit is provided between the packet switching unit and the multiplexer. The packet rate monitoring circuit includes a circuit for monitoring the cell arrival rate, a circuit for detecting a packet cell violating the declared value which is transmitted from the terminal, a circuit for adding a mark representative of the violation cell to the violation packet which is detected by the detecting circuit, and a circuit for automatically modifying the declared parameter.

Abstract: There is provided a packet-rate control method for a packet network, in which a declaration of parameters indicating the rate of fixed-length packets is so made to a call control system by a subscriber terminal device prior to communication as to be associated with a logical channel number. The rate of packets inputted to the network is so measured as to be associated with a logical channel number. While the degree of violation is low, packets transmitted in violation of user-declaring parameters are provided with a violation mark and taken in the network. If the degree of violation is high, the packets transmitted in violation of user-declaring parameters are discarded on the input side of the network. When there appears a possibility of congestion in the network, the marked packets are discarded. As a result, it is possible to prevent violation packets and marked packets from affecting the quality of service using normal packets.