A switching device comprising several input ports and several output ports, whereby each of the input ports is connectable to a corresponding switch adapter. At least one switch controller controls the routing of incoming data packets from the input ports to the output ports. For each output port a congestion controller is arranged which in operation, generates grant information which signals whether the switch adapters are allowed to send the data packet to the output port. For each of the input ports a data packet access controller marks a data packet as non-compliant if the packet was erroneously sent from said output port.