Patent ID: 7469298
Filing Date: 2008-12-23
Classification: H04L

Abstract:
1. A communication system comprising: (a) an access network on which a virtual private network is established; (b) a service provider coupled to said access network; and (c) user terminals comprising: a user-side session management unit that performs processing for designation of the service provider, user authentication, and IP address assignment, by using a signaling protocol to exchange management frames with the access network in an authentication phase, and a main-signal transmission-and-reception unit that exchanges main-signal frames with said service provider by using IPoE protocols over the virtual private network established on said access network in a communication phase, wherein the main-signal frames being distinguishable from the management frames on the basis of Ether Type field values as part of Layer 2 header information; and (d) a subscriber-side edge switch placed between said access network and said user terminal, comprising; a transfer control unit that transfers a first main signal frame from the user terminal to the access network and a second main-signal frame from the access network to the user terminal, and a said network-side session management unit performs processing for signaling control, wherein said transfer control unit attaches to the first main-signal frame a tag indicating the first virtual private network when transferring the first main-signal frame from the user terminal to the access network, and said transfer control unit removes a tag indicating the virtual private network from the second main-signal frame when transferring the second main-signal frame from the access network to the user terminal, said network-side session management unit comprises a first table indicating correspondences between the Layer 2 address of said user terminal and a session involving said user terminal, and performs processing for signaling control by software using the first table, said transfer control unit comprises a second table indicating correspondence between the Layer 2 address of the user terminal and the tag indicating the virtual private network connected to said service provider, said transfer control unit further comprises a third table indicating forwarding information corresponding to said service provider, said transfer control unit further comprises a fourth table indicating attributes of each port of said subscriber-side edge switch, said transfer control unit controls the transfer of said main-signal frames by hardware processing using the second, third, and fourth tables, and said transfer control unit performs processing for determination of whether or not an input frame is to be handled by the subscriber-side edge switch, and whether an output frame is to be tagged or untagged, and whether or not broadcast filtering is activated, and filtering of unicast flooding, based on said at least one attribute indicated in said fourth table.