Communication terminal, method of communication and communication system

A communication terminal comprises: first means that communicates with a network system that includes a forwarding apparatus forwarding a packet and a control apparatus informing the forwarding apparatus of a processing rule prescribing a packet processing method; second means that determines a processing operation to be executed by the network system from among packet processing operations to be executed by the communication terminal; and third means that informs the forwarding apparatus of a processing rule corresponding to the determined packet processing operation. The load on a communication terminal due to packet processing operation is reduced.