Method and apparatus to provide facility and module redundancy in telecommunication switching equipment

A method providing equipment and facility redundancy for ATM circuitry which carriers out ATM functions, comprising:

• performing a group of ATM functions with first circuitry on a first stream of ATM cells producing a processed first stream;
• performing the ATM functions with second circuitry on a second stream of ATM cells producing a processed second stream, the second stream being identical to the first stream, the first circuitry and the second circuitry implementing the ATM functions, the first circuitry and the second circuitry being synchronized to each other;
• and
• in a cross point switch having N input ports capable of receiving the first processed stream and the second processed stream and N output ports coupled to N input ports of an N×N switch fabric, coupling the first processed stream to a first input port of the N×N switch fabric in a first configuration and coupling the second processed stream to the first input port of the N×N switch fabric in place of the first processed stream in a second configuration upon detection of an error condition in the first circuitry, thereby providing redundancy protection for the ATM functions;
• wherein the ATM functions include the multiplexing, SONET framing, routing, and user parameter control.

A redundant telecommunication switch comprising:

• a primary input interface comprising N communication paths capable of receiving N input data streams and outputting N processed data streams;
• a secondary input interface comprising N communication paths capable of receiving copies of said N input data streams and outputting N copy data streams corresponding to the N processed data streams output from the primary input interface, wherein the secondary input interface is functionally identical to the primary input interface;
• a switch fabric having 2N input ports and 2N output ports, wherein each of the 2N input ports may be connected to each one of the 2N output ports;
• and
• a first cross point switch having first N input ports capable of receiving the N processed data streams from the primary input interface and second N input ports capable of receiving the N copy data streams from the secondary input interface, wherein the first cross point switch couples the N processed data streams from the primary input interface to N inputs ports of the switch fabric in a first configuration, and wherein the first cross point switch is capable of detecting an error in a first processed data stream output from the primary input interface and, in response to the detection, switching a corresponding first copy data stream to a first input port of the switch fabric in place of the first processed data stream in which the error was detected;
• wherein the primary input interface includes a plurality of first ATM channels performing ATM functions on the input data streams and the secondary input interface includes a plurality of second ATM channels performing the ATM functions on the copies of the input data streams;
• and
• wherein one of the first ATM channels and one of the second ATM channels includes the multiplexing, SONET framing, routing, and user parameter control.