Patent ID: 7616645
Filing Date: 2009-11-10
Classification: H04L

Abstract:
1. A frame forwarding apparatus equipped with a plurality of line interfaces, connected to an IP packet forwarding apparatus through one of said line interfaces and connected to subscriber terminals through the other line interfaces, said frame forwarding apparatus comprising: a line information table comprising a plurality of entries, each defining a line number of a physical line connected to one of said line interfaces and flag information for indicating whether the physical line is connected to said IP packet forwarding apparatus or to one of said subscriber terminals; a VLAN bundling table comprising a plurality of entries, each defining the correspondence of subscriber side line information with IP packet forwarding apparatus side line information and subscriber terminal's MAC address; and a frame forwarding processing unit for controlling forwarding of frames each including a VLAN identifier, between each of said subscriber terminals and said IP packet forwarding apparatus, wherein each entry of said VLAN bundling table includes a physical line number and a subscriber VLAN identifier defined on the physical line having the physical line number as said subscriber side line information and a physical line number of the physical line connected to said IP packet forwarding apparatus and a group VLAN identifier defined on the physical line as said IP packet forwarding apparatus side line information, and at least one group of the entries in said VLAN bundling table includes the same group VLAN identifier as each other as said IP packet forwarding apparatus side line information, wherein when a frame is received through one of said line interfaces, said frame forwarding processing unit (1) judges whether the frame is received from one of said subscriber terminals or from said IP packet forwarding apparatus by referring to the flag information in said line information table based on the line number of the physical line connected to the one line interface; (2) converts, by referring to said VLAN bundling table, the subscriber VLAN identifier given in the frame into the group VLAN identifier defined in one of said entries when the frame is judged as one having been received from one of said subscriber terminals, and forwards the frame to said IP packet forwarding apparatus; and (3) converts a group VLAN identifier given in the frame into the subscriber VLAN identifier defined in one of said entries when the frame is judged as one having been received from said IP packet forwarding apparatus and addressing one of said subscriber terminals with a destination MAC address, and forwards the frame to one of said physical lines corresponding to the destination subscriber terminal through one of said line interfaces.