Patent ID: 7672301

Claim:
A Clos switching network, comprising: a first switching stage comprising a plurality of first stage switching devices; a second switching stage comprising a plurality of second stage switching devices; and a distribution stage coupled to said first switching stage and said second switching stage, said distribution stage configured to receive a plurality of bandwidth units (BU's) from each first stage switching device, and to distribute at least one BU from each first stage switching device to each second stage switching device, such that each second stage switching device is assured of receiving at least one BU from each first stage switching device, and wherein said distribution stage comprises mapping circuitry configured to provide fixed mapping of BU's and said distribution stage is not a dynamically configurable switching device; wherein the distribution stage enables a Clos architecture in the switching network without requiring physical ports from each of the plurality of first stage switching devices to physical ports on each of the plurality of second stage switching devices; wherein said distribution stage distributes a uniform number of BU's from each of said first stage switching devices to each of said second stage switching devices; and wherein the distribution stage enables said Clos architecture with a total number of physical ports from the plurality of first stage switching devices less than the total number of physical ports to the plurality of second stage switching devices.