Patent ID: 8670346

Claim:
An apparatus for performing packet classification of data packets belonging to a packet flow through a packet data network, the apparatus comprising: an ingress interface configured to receive packets of said packet flow; an active filter configured to change one of at least one packet and at least one characteristic of the packet flow; an egress interface configured to send, towards a destination, the packets including the change of one of the at least one packet and at least one characteristic of the packet flow; a monitor configured to monitor one of said packet flow and at least one associated packet flow received by the apparatus to detect reactions in the packet flow caused by the change of one of the at least one packet and at least one characteristic of the packet flow; and a flow classifier configured to: attempt to classify a received packet flow using at least one of a plurality of passive classifiers each relying upon characteristics of the received flow without the interruption of the changed one of the at least one packet and at least one characteristic of the packet flow into the flow wherein said active filter is applied only if the flow cannot be classified by the one or more passive classifiers; and if the flow cannot be classified by the one or more passive classifiers, attempt to classify the flow into one of a set of defined classes according to a detected reaction.