N×N crossbar packet switch

A crossbar switch for a network, said crossbar switch being an N×N switch having N input ports each with a plurality of buffers capable of storing one data cell each, and N output ports each with a plurality of buffers capable of storing one data cell each, for switchably coupling any of said N input ports to any of said N output ports, wherein

• said switch contains N output port arbiters, said N arbiters operating asynchronously with respect to each other,
• each of said N input ports includes a data cell scheduler, each said scheduler being operative to forward a special flag with the data cells to signal start-of-cell and end-of-cell,
• said N arbiters and said N schedulers are interconnected by 2×N×N control lines,
• said switch output ports operating under an arbitration protocol controlling use of said 2×N×N control lines, said protocol being operative to support the indication of;
• output port busy serving another input port
• output port active
• output port not operational
• output port accepting a data cell from an input port, and having free output port buffers within a virtual channel and/or priority class for this accepted
• output port accepting a data cell from an input port but not having free output port buffers within a virtual channel and/or priority class for that accepted data cell,
• whereby said switch is able to support transmission of non-fixed size data cells.