Patent ID: 7835355
Filing Date: 2010-11-16
Classification: H04L

Abstract:
1. A packet forwarding apparatus to be located in an access network and connected between a plurality of user terminals and a plurality of redundant gateways each connected to an Internet transit network, the packet forwarding apparatus comprising: a plurality of line interfaces each for communicating with one of said user terminals or one of said gateways; and a protocol processing unit for controlling packet forwarding among said line interfaces and for forwarding, upon receiving a connection initiation request packet having a header including one of a broadcast address and a multicast address as its destination address and transmitted from one of said user terminals to connect the user terminal to the Internet transit network, the connection initiation request packet to said plurality of gateways, said protocol processing unit having a management table for storing forwarding control information to control forwarding of communication control packets, in association with an identifier of each user terminal, wherein said protocol processing unit selects one of response packets replied from said plurality of gateways in response to the connection initiation request packet, forwards the selected response packet to the user terminal from which the connection initiation request packet has been transmitted, and updates said management table so that the other response packets received thereafter are discarded based on the forwarding control information corresponding to the user terminal, wherein said management table comprises a plurality of table entries each indicating the correspondence of an address of one of said user terminals, from which said connection initiation request packet was transmitted, to status information indicating the type of a communication control packet in a reception waiting state, and said protocol processing unit operates to add a new table entry into said management table when a new connection initiation request packet was received from one of said user terminals, said new table entry including an address of the user terminal, as said user terminal identifier, extracted from the header of the received connection initiation request packet and status information indicating that a response packet to the connection initiation request is in a reception waiting state; to judge when a response packet to the connection initiation request packet was received, whether the received response packet should be forwarded to the user terminal or discarded based on the status information in a table entry that includes the user terminal address matched with a destination address in the header of the received response packet; and to change the status information to a reception waiting state of another communication control packet determined depending on a communication control procedure when the received response packet is forwarded to the user terminal so that a response packet received thereafter is discarded by reason of a difference in the type from the communication control packet in the reception waiting state.