Methods and apparatus for flexible device interface port assignment in a data communications switching system

A communication network comprising a plurality of switching apparatuses, each of said plurality of switching apparatuses capable of selectively coupling M external devices to internal network links of said communication network, wherein each of said plurality of switching apparatuses comprises:

• an N×N output switching stage having N input interfaces and N output interfaces, wherein said N output interfaces are capable of being coupled to said internal network links of said communication network;
• a programmable M×N input switching stage having M input ports and N output ports, wherein M is greater than N, and wherein each of said M input ports is capable of being coupled to one of said M external devices and each of said N output ports is coupled to one of said N input interfaces of said N×N output switching stage;
• and
• a controller capable of controlling said programmable M×N input switching stage such that each one of said M external devices may be selectively coupled and decoupled to one of said N input interfaces of said N×N output switching stage according to a level of service associated with said each one of said M external devices.

A switching apparatus capable of selectively coupling M external devices to a communication network, said switching apparatus comprising:

• an N×N output switching stage having N input interfaces and N output interfaces, wherein said N output interfaces are capable of being coupled to said communication network;
• a programmable P×Q input switching stage having P input ports and Q output ports, wherein each of said P input ports is capable of being coupled to one of said M external devices and each of said Q output ports is coupled to one of said N input interfaces of said N×N output switching stage;
• a programmable R×S input switching stage having R input ports and S output ports, wherein each of said R input ports is capable of being coupled to one of said M external devices and each of said S output ports is coupled to one of said N input interfaces of said N×N output switching stage, wherein at least one of said S output ports may be coupled to the same one of said N input interfaces of said N×N output switching stage as one of said Q outputs of said programmable P×Q input switching stage;
• and
• a controller capable of controlling said programmable P×Q input switching stage and said programmable R×S input switching stage such that each one of said M external devices may be selectively coupled and decoupled to one of said N input interfaces of said N×N output switching stage according to a level of service associated with said each one of said M external devices.

A communication network comprising a plurality of switching apparatuses, each of said plurality of switching apparatuses capable of selectively coupling M external devices to internal network links of said communication network, wherein each of said plurality of switching apparatuses comprises:

• an N×N output switching stage having N input interfaces and N output interfaces, wherein said N output interfaces are capable of being coupled to said communication network;
• a programmable P×Q input switching stage having P input ports and Q output ports, wherein each of said P input ports is capable of being coupled to one of said M external devices and each of said Q output ports is coupled to one of said N input interfaces of said N×N output switching stage;
• a programmable R×S input switching stage having R input ports and S output ports, wherein each of said R input ports is capable of being coupled to one of said M external devices and each of said S output ports is coupled to one of said N input interfaces of said N×N output switching stage, wherein at least one of said S output ports may be coupled to the same one of said N input interfaces of said N×N output switching stage as one of said Q outputs of said programmable P×Q input switching stage;
• and
• a controller capable of controlling said programmable P×Q input switching stage and said programmable R×S input switching stage such that each one of said M external devices may be selectively coupled and decoupled to one of said N input interfaces of said N×N output switching stage according to a level of service associated with said each one of said M external devices.