COMMUNICATION APPARATUS, COMMUNICATION METHOD, AND PROGRAM THEREOF

PROBLEM TO BE SOLVED: To shorten a time from the instruction of communication start or reception by a user to the transmission of a communication start/reception information in the case of performing communication where a plurality of pieces of information such as sound and video images are integrated. SOLUTION: Immediately after start instruction information is received, a control means 14 allows a port request information transmitting means 11 to transmit, to a router, port request information which indicates the usage request of a port number including the port number and the address of a communication apparatus, allows a port usability information receiving means 12 to receive port usability information which indicates the usability of the port number to be returned from the router, allows a port storage means 13 to store the port usability information in response to the port number, and then, performs communication with the use of the port number that the port usability information stored in the port storage means 13 indicates usable. COPYRIGHT: (C)2005,JPO&NCIPI