Abstract: The present invention provides for an ATM switch for transferring ATM cells from input channels to output channels. The switch has a plurality of input and output ports, each connected to input and output channels respectively. The ATM switch also has a switch block connected between each one of the input ports and each one of the output ports to convey the cells from the input ports to the output ports, and a backpressure signal circuit. Each input port has an input buffer which holds cells which arrive faster from an input channel than the input port can transmit to the switch block, and each output port has an output buffer holding cells when the cells arrive faster from the switch block than the output port can transmit. The backpressure signal circuit sends a signal from a congested output buffer to those input port buffers which have transmitted a cell to the output buffer (during congestion) so that the input port buffers cease transmission.

Abstract: An ATM switch with a switch queuing system which minimizes cell loss for bursty traffic, while avoiding delay for time-critical. The switch has a plurality of input ports and a plurality of output ports, a switch fabric transmitting cells from the input ports to the output ports, and a backpressure signal circuit connected between each output buffer of each output port and each input buffer of each input port. Each input port has an input buffer holding ATM cells when the cells arrive faster from the port's input channel than the input port can transmit. The input port transmits cells from its input buffer responsive to a plurality of priority levels. Each output port has an output buffer holding cells when the cells arrive faster from the input ports than the output port can transmit. The output port also transmits cells from its output buffer responsive to a plurality of priority levels.

Abstract: Switch architecture is provided for interfacing a high speed broad bandwidth communication network to a communication fabric having a bandwidth which is a fraction of the high speed broad bandwidth with the network and the fabric having different data packet formats. A multiplex/inverse multiplex unit is provided for converting data packets at the first carrier rate and in the first format to data packets in the second format, and a switch converter then converts the data packet headers in the second format into switch format headers for transmission of the data packets through ports of the communication fabric. A splitter receives the data packets from the switch converter and routes the data packets to one of a plurality of the fabric ports in accordance with the connection identifier in the switch format header, the data packets to one of a plurality of fabric ports being at a second carrier rate.