US 5,497,369 A · Multicast switch circuits

Abstract

A multicast switch fabric is described wherein blocking of desired signal paths is handled by storing a cell to be transmitted through the fabric at a buffer at an input port to the fabric and attempting to retransmit the cell through the fabric until the cell is successfully transmitted, or a maximum number of retries at transmission is reached. Each switch element in the fabric has a block register which stores information as to whether or not a request path including that element is blocked, the block signals being fed back to the input port to indicate whether or not cell transmission has been successful. A 2.times.2 switch element is described wherein header information from the cell is decoded in two subfields, one field determining the number of copies to be replicated in the switch and a second field determining if the cell is to be fully replicated at each subsequent stage of the fabric.

Claims15

Dependent claims

A multicast switch element for connection to a plurality of similar such elements in a matrix to form a multicast switch fabric, said multicast switch element having:

a plurality of inputs, each of the inputs being responsive to cells containing information and associated instructions, the instructions including a first section indicative of quantity of cell information replication to be performed by the switch element and a second section indicative of whether or not the information is to be replicated fully in any subsequent switch element in the matrix;
a plurality of outputs;
and
a switch coupled between said plurality of inputs and said plurality of outputs, said switch including means for decoding the first section and the second section of cell instructions received by the switch to obtain decoded instructions and for providing replicated cell information to the outputs in accordance with the decoded instructions.

1 more element

A method of replicating cells containing information and associated instructions in a multicast switch fabric having a plurality of switch elements connected in a matrix, the instructions including a first section indicative of quantity of cell information replication to be performed by the switch elements and a second section indicative of whether or not the information is to be replicated fully in any subsequent switch element in the matrix;

comprising the steps, for each switch element of:
decoding the first section of said instructions in a cell entering that switch element to determine the quantity of cell information replication to be performed within that switch element;
decoding the second section of said instructions to determine whether or not the information in said cell is to be replicated fully in any subsequent switch elements which said cell subsequently enters in the multicast switch fabric;
replicating said information contained in said cell in accordance with said decoding of the first section of said instructions;
and
determining content of instructions included in any cell exiting that switch element, in accordance with said decoding of the second section of said instructions in said cell entering that switch element.

3 more elements

Dependencies are inferred from the claim text.

Multicast switch circuits

Life of this patent

Multicast switch circuits

Life of this patent

Abstract

Claims15