Abstract: A packet switch has a switching unit (SU) for switching packets between network links and a computing unit (CU) connected to the SU through a network link for implementing software control functions over the SU. The SU is formed of different functional components interconnected by generic buses. The components communicate with one another using program data units (PDUs) that are formatted and transmitted according to a shared device protocol. The communication between the components occurs by placing PDUs in bus frames that are passed from component to component. Information is exchanged between the components by adding information to or dropping information from the fields of the PDUs, or by concatenating new fields to the PDUs, as the frames pass from component to component. By using a generic bus to implement PDU-based interconnections within the SU, all the components are forced to support a common interface.

Abstract: A communication system consisting of a number of modules that communicate with one another through a shared communications bus which accommodates different protocols. The system includes a bus clock for defining a frame having a plurality of time slots for communicating signals on the bus; and a bus management algorithm for specifying a receive assignment definition and a transmit assignment definition. The receive assignment definition defines a receive channel for each of the modules representing a set of the time slots, where the modules receive signals from the bus during the set of time slots prescribed by the receive channel. The transmit assignment definition defines a transmit channel for each of the modules representing a set of the time slots, where the modules transmit signals to the bus during the set of time slots prescribed by the transmit channel.

Abstract: A data packet processing system is provided for a router having a multiprocessor architecture comprising a master node and a processor array of multiple slave nodes. A packet switching software of the router is partitioned into a main forwarding program which is loaded in the master node, and a set of procedures which is loaded into the slave nodes. The system assigns to each data packet a program counter which defines a sequence of procedural calls in the main forwarding program. By stepping through the program counter in the master node, each procedural call is forwarded to and executed by one of the slave nodes.

Abstract: Communication paths in a digital key telephone system are operated by sequentially transferring bit states from origin channels associated with communication ports to exclusively dedicated time slots in a parallel transmission medium. Time slot bit states are selectively stored at designated memory locations corresponding to destination channels associated with the communication ports. The memory locations are read in synchronism with the channel occurrences and bit states from the designated memory locations are asserted in the corresponding channels, any remaining channels having predetermined bit states asserted therein.

Abstract: A simple but versatile communication switching system suitable for air traffic control and the like applications is provided. The system utilizes a central pulse amplitude modulation bus, is modular in structure, and provides the time division multiplexed representations of the auxiliary circuit terminations, such as radio and trunk circuits, on the central bus for direct access by all modules.