Abstract: A packet control means for checking packets according to a plurality of rules, in which each packet is associated with a control value; the packet control means comprising index means for generating an index value from the control value associated with a packet and means for using the index value to access a rule for checking the packet from the plurality of rules. The control value is set by the packet control means. Advantageously, the packet checking always requires a single access to the plurality of rules, allowing for faster operation.