Subscriber line accommodation apparatus and packet filtering method

A subscriber line accommodation apparatus characterized by comprising:

• subscriber line termination units which individually terminate a plurality of subscriber lines;
• an address information acquisition unit which successively acquires, as address information, a dynamic address dynamically assigned to each of communication terminals connected to the subscriber lines terminated by said subscriber line termination units;
• a packet information reading unit which reads out, from a packet to be sent to one of the communication terminals, packet information containing a dynamic address indicating a destination of the packet;
• an address information coincidence presence/absence determination Unit which determines whether the dynamic address read out by said packet information reading unit coincides with one of pieces of address information acquired by said address information acquisition unit;
• and a packet sending control unit which permits sending of only a packet determined to be coincident by said address information coincidence presence/absence determination unit;
• wherein said address information acquisition unit successively acquires, as the address information, a set of an absolute address uniquely assigned to the communication terminal and a dynamic address dynamically assigned to the absolute address,
• the packet information reading unit reads out, from the packet to be sent to one of the communication terminals, packet information containing the set of the absolute address and the dynamic address and indicating the destination of the packet, and
• said address information coincidence presence/absence determination unit determines whether the set of the absolute address and the dynamic address read out by said packet information reading unit coincides with one of pieces of address information acquired by said address information acquisition unit;
• wherein said address information acquisition unit successively acquires, as the address information, a set of an absolute address uniquely assigned to the communication terminal, a dynamic address dynamically assigned to the absolute address, and a subscriber line number related to the subscriber line which has acquired the dynamic address,
• the packet information reading unit reads out, from the packet to be sent to one of the communication terminals, packet information containing the set of the absolute address, the dynamic address, and the subscriber line number and indicating the destination of the packet, and
• said address information coincidence presence/absence determination unit determines whether the set of the absolute address, the dynamic address, and the subscriber line number read out by said packet information reading unit coincides with one of nieces of address information acquired by said address information acquisition unit.