US 6,151,301 AGranted

ATM architecture and switching element

AssigneePMC-Sierra, Inc.

InventorBrian D. Holden

Life of this patent

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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.

Claims4

Dependent claims

In an ATM switching matrix having a plurality of switching elements interconnected in a switch fabric architecture, each said switching element comprising:

a data input for receiving cells from an ATM cell output of a source, said source being a routing table or a data output of another of said switching elements;
a data output for sending cells to an ATM cell input of a destination, said destination being a routing table or a data input of another of said switching elements;
a cell buffer in data communication with said data input and said data output;
an input cross-point block coupled between said data input and said cell buffer;
an output cross-point block coupled between said cell buffer and said data output;
a back-pressure output able to be coupled to said source for issuing a back-pressure signal to said source to block transmission of cells by said source to said data input;
control means coupled to said back-pressure output for asserting said back-pressure signal responsive to congestion locally within said switch element;
and
a buffer control circuit coupled to said cell buffer and configured to control transmission of cells, said buffer control circuit further configured to receive a back-pressure signal from another of said switching elements and to control transmission of cells in response to a received back-pressure signal.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/680,869Filed 16 Jul 1996 · continuation
Priority: 11 May 1995
Granted: 21 Nov 2000
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

H04L 12/5601
Packet switching systems: transfer mode dependent, e.g. ATM
H04L 49/108
ATM switching elements: using shared central buffer
H04L 49/203
Multicast operation; Broadcast operation: aTM switching fabrics with multicast or broadcast capabilities
H04L 49/255
Using establishment or release of connections between ports: control mechanisms for ATM switching fabrics