Abstract: A method and apparatus are described for transmitting data cells in an ATM network having a plurality of connections. A first number of tokens are allocated to a selected one of the plurality of connections. Data cells are transmitted from the selected connection at a peak cell rate while the first number is greater than zero. The first number is decremented by one for each data cell transmitted by the selected connection at the peak cell rate. Data cells are then transmitted from the selected connection at a sustainable cell rate which is less than the peak cell rate while the first number is zero. The first number is incremented by a variable increment during an idle period in which the selected connection does not transmit data cells. The variable increment increases in value as the idle period increases in duration.

Abstract: An ATM switching system architecture of a switch fabric-type is built of, a plurality of ATM switch element circuits and routing table circuits for each physical connection to/from the switch fabric. A shared pool of memory is employed to eliminate the need to provide memory at every crosspoint. Each routing table maintains a marked interrupt linked list for storing information about which ones of its virtual channels are experiencing congestion. This linked list is available to a processor in the external workstation to alert the processor when a congestion condition exists in one of the virtual channels. The switch element circuit typically has up to eight 4-bit-wide nibble inputs and eight 4-bit-wide nibble outputs and is capable of connecting cells received at any of its inputs to any of its outputs, based on the information in a routing tag uniquely associated with each cell.

Abstract: An ATM switching system architecture of a switch fabric-type is built of, a plurality of ATM switch element circuits and routing table circuits for each physical connection to/from the switch fabric. A shared pool of memory is employed to eliminate the need to provide memory at every crosspoint. Each routing table maintains a marked interrupt linked list for storing information about which ones of its virtual channels are experiencing congestion. This linked list is available to a processor in the external workstation to alert the processor when a congestion condition exists in one of the virtual channels. The switch element circuit typically has up to eight 4-bit-wide nibble inputs and eight 4-bit-wide nibble outputs and is capable of connecting cells received at any of its inputs to any of its outputs, based on the information in a routing tag uniquely associated with each cell.