Non-blocking grooming switch
AssigneeLSI Logic Corporation
InventorsEphrem C. Wu, Robert Hong
Life of this patent
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Abstract
A grooming switch comprises plural input ports for receiving multi-time-slot input signals and plural output ports for forwarding multi-time-slot output signals. At least five switching stages alternate between time switching and space switching. The first stage is connected to the input ports, and the last stage is connected to the output ports. Each intermediate stage is connected to two other stages. Collectively, these stages perform compact superconcentration of the input signals, copying and distribution of the compact superconcentrated signals, and unicast switching of the distributed signals to form the output signals, resulting in a grooming switch that is rearrangeably non-blocking for arbitrary multicast traffic.
Claims41
A grooming switch comprising:
- a plurality of switching stages arranged as (i) at least five sequential stages, (ii) alternating between time switching and space switching, (iii) a first of the switching stages connected to a plurality of input ports, (iv) a last of the switching stages connected to a plurality of output ports, and (v) a plurality of intermediate stages of the switching stages, wherein each of the intermediate stages connects to two other of the switching stages, the switching stages collectively performing:
- (A) concentrating a plurality of input signals to generate a plurality of compact signals,
- (B) copying the compact signals to generate a plurality of distributed signals, and
- (C) unicast switching the distributed signals to generate a plurality of output signals, wherein the grooming switch is rearrangeably non-blocking for arbitrary multicast traffic within the input signals.
A method for routing packets through a grooming switch, comprising the steps of:
- (A) for each of a plurality of input ports, concentrating a plurality of input signals in a first timeslot interchange of a plurality of switching stages arranged as at least five sequential stages to generate a plurality of compact signals;
- (B) copying the compact signals to generate a plurality of distributed signals, the copying using both (i) a first space switch of the switching stages and ii a second timeslot interchange of the switching stages according to one or more fanout criteria of the input signals;
- and
- (C) unicast switching the distributed signals to generate a plurality of output signals, the unicast switching using both (i) a second space switch of the switching stages and (ii) a third timeslot interchange of the switching stages according to one or more routing criteria of the input signals, wherein each of the output signals has multiple output time slots.
A grooming switch comprising:
- in each of a plurality of input ports, means for concentrating the input signals in a first timeslot interchange of a plurality of switching stages arranged as at least five sequential stages to generate a plurality of compact signals;
- means for copying the compact signals to generate a plurality of distributed signals, the copying using both (i) a first space switch of the switching stages and (ii) a second timeslot interchange of the switching stages and according to fanout criteria of the input signals;
- and
- means for unicast switching the distributed signals to generate a plurality of output signals, the unicast switching using both (i) a second space switch of the switching stages and (ii) a third timeslot interchange of the switching stages according to one or more routing criteria of the input signals, wherein each of the output signals has multiple output time slots.
Dependencies are inferred from the claim text.