Abstract: A system for connecting low-cost, simple peripherals to an ATM network is disclosed. A plurality of such devices is connected to a standard ATM switch in a ring configuration. A polling station, located remotely in the ATM network, periodically generates a token cell which is delivered to the switch and, thereafter, is transmitted onto the ring configuration. The devices transmit cells in response to the token cells by transmitting cells behind the token cell as they forward it around the ring. The resultant cell chain is received at the ATM switch, where the cells are then sent onto the ATM network using virtual circuits.

Abstract: A switching device for switching ATM cells from a plurality of network input links to a plurality of network output links comprises a plurality of ports containing line interfaces and input and output buffers, a hardware switch controller, a microprocessor, and memory for storing routing tables and system software. All these elements are interconnected via a processor bus, and additionally, the ports are interconnected by a separate switching bus. The switch controller employs hash-based routing table indexing to route cells from selected input ports to appropriate output ports according to the cells' header information. Switch requests generated by incoming cells are arbitrated using a token bus allocation scheme. The majority of cells are switched almost entirely in hardware, but the microprocessor can assume control of the switching architecture to resolve exception conditions and to perform special processing on selected virtual circuits.