Method and apparatus for distribution/consolidation (DISCO) interface units for packet switched interconnection system

In a communication system within which is disposed an interconnection subsystem for routing data packets between a plurality of signal lines, said interconnection subsystem including a plurality of packet consolidation interfaces for multiplexing said data packets from a plurality of said signal lines into a higher-rate signal line, a method of testing said packet consolidation interfaces comprising the steps of:

• connecting first and second of said packet consolidation interfaces to a selected one of said signal lines in order that said first and second packet consolidation interfaces receive an identical sequence of said data packets;
• equalizing said first and second packet consolidation interfaces in order that said first packet consolidation interface accumulates a first set of said data packets and said second packet consolidation interface accumulates a second set of data packets identical to said first set of data packets;
• and
• latching, at output ports of said first and second packet consolidation interfaces, selected information included within corresponding ones of said data packets from said first and second sets of said data packets and comparing said selected information latched from said corresponding ones of said data packets;
• wherein a difference between said selected information latched from said corresponding ones of said data packets indicates said first packet consolidation interface differs from said second packet consolidation interface.

In a communication system within which is disposed an interconnection subsystem for routing data packets between a plurality of signal lines, said interconnection subsystem including a plurality of packet distribution interfaces for allocating data packets from a high-rate signal line to a plurality of lower-rate signal lines, a method of testing said packet distribution interfaces comprising the steps of:

• configuring first and second of said packet distribution interfaces to receive an identical sequence of said data packets from said high-rate signal line;
• equalizing said first and second packet distribution interfaces in order that said first packet distribution interface accumulate a first set of said data packets and said second packet distribution interface accumulate a second set of data packets identical to said first set of data packets;
• and
• latching, at output ports of said first and second packet distribution interfaces, selected information included within corresponding ones of said data packets from said first and second sets of said data packets and comparing said selected information latched from said corresponding ones of said data packets;
• wherein a difference between said selected information latched from said corresponding ones of said data packets indicates said first packet distribution interface differs from said second packet distribution interface.

In a communication system within which is disposed an interconnection subsystem for routing data packets between a plurality of signal lines, said interconnection subsystem including a plurality of packet distribution interfaces for allocating data packets from a high-rate signal line to a plurality of lower-rate signal lines, a method of providing redundancy among said interface units comprising the steps of:

• allocating by a first one of said interface units selected data packets from said high-rate signal line to a first of said lower-rate signal lines;
• configuring a roving one of said interface units to monitor said selected data packets;
• equalizing said first and said roving ones of said interface units so that first and second identical sets of data packets from said high-rate signal line are accumulated within each;
• latching, at predefined locations within said first and said roving ones of said interface units, selected information included within said first and second sets of data packets and comparing said selected information latched from said first and second sets of data packets;
• disabling said first one of said interface units from allocating said selected data packets to said first of said lower-rate signal lines;
• and
• allocating by said roving one of said interface units selected data packets from said high-rate signal line to said first of said lower-rate signal lines.

In a communication system within which is disposed an interconnection subsystem for routing data packets between a plurality of signal lines, said interconnection subsystem including a plurality of packet consolidation interfaces for allocating data packets from a plurality of lower-rate signal lines to a high-rate signal line, a method of providing redundancy among said interface units comprising the steps of:

• allocating by a first one of said interface units data packets from a first of said lower-rate signal lines to said high-rate signal line;
• connecting a roving one of said interface units to said first of said lower-rate signal lines;
• equalizing said first and said roving ones of said interface units so that first and second identical sets of data packets from said first of said lower-rate signal lines are accumulated within each;
• latching, at predefined locations within said first and said roving ones of said interface units, selected information included within said first and second sets of data packets and comparing said selected information latched from said first and second sets of data packets;
• disabling said first one of said interface units from allocating said selected data packets to said high-rate signal line;
• and
• allocating by said roving one of said interface units data packets from said first of said lower-rate signal lines to said high-rate signal line.

In a communication system within which is disposed an interconnection subsystem for routing data packets between a plurality of signal lines, said interconnection subsystem including a plurality of interface units coupled to said signal lines, a system for testing said interface units comprising:

• a multiplexer for connecting first and second of said interface units to receive first and second identical sequences of said data packets from a first of said signal lines;
• an equalization circuit for equalizing said first and second interface units so that said first interface unit accumulates a first set of said data packets and said second interface unit accumulates a second set of data packets identical to said first set of data packets;
• first and second output interfaces, respectively disposed at predefined locations within said first and second interface units, for respectively latching corresponding data packets within said first and second sets of data packets;
• and
• a comparator for comparing said corresponding data packets latched within said first and second output interfaces and for generating an error signal when a difference exists therebetween;
• wherein generation of said error signal indicates that said first interface unit is operating differently from said second interface unit.

In a communication system within which is disposed an interconnection subsystem for routing data packets between a plurality of signal lines, said interconnection subsystem including a plurality of interface units coupled to said signal lines, a system for providing redundancy among said interface units comprising:

• a multiplexer network for connecting a first one of said interface units and a roving one of said interface units to a first of said signal lines;
• a equalization circuit for equalizing said first and said roving one of said interface units so that first and second identical sets of data packets from said first signal line are accumulated within said first and said roving one of said interface units;
• first and second output interfaces, respectively disposed at predefined locations within said first and said roving ones of said interface units, for latching selected information included within said first and second identical sets of data packets;
• a comparator for comparing said selected information latched within said first and second output interfaces and for generating an error signal when a difference exists therebetween;
• and
• an interconnection controller means for notifying a communication system controller upon generation of said error signal.