Patent ID: 8064445

Claim:
A layer 2 mobility network comprising: a layer 2 switch that is a base of a heterogeneous wireless access system; an IP multicast router that performs a mutual connection in an IP layer with an external network to which a source of a multicast communication is connected; and a gateway switch interposed between a plurality of the layer 2 switches and the IP multicast router connected via a relay transfer path, wherein: a radio access point of the heterogeneous wireless access system or the layer 2 switch is configured as an apparatus located at an edge of the network for selectively performing first and second functions for executing multicast delivery to a mobile terminal in response to receiving a report message in a multicast procedure transmitted by the mobile terminal, the apparatus located at the edge of the network and the gateway switch each maintains a management table for managing the multicast delivery, the first function is a function of transmitting the report message to the gateway switch, and the second function is a function of snooping the report message to learn a transfer route for the multicast delivery, and transmitting an entry update request frame in a direction of the gateway switch for causing the gateway switch to learn an entry, in the management table of the gateway switch, forming the learned transfer route for the multicast delivery, upon receiving the report message, the apparatus located at the edge of the network determines whether or not to perform the first and second functions by referring to the management table of the apparatus to check whether a same multicast group and a same distribution source have already been requested, the apparatus determining to perform the first and second functions when the same multicast group and the same distribution source have not been requested, and upon receiving a report message in the multicast procedure transmitted from the apparatus located at the edge of the network, the gateway switch is configured to perform functions of: registering a multicast group/source combination, distribution to which is requested, in the management table of the gateway switch; and transferring the received report message to a port to which the IP multicast router is connected after receiving the entry update request frame transmitted from the apparatus located at the edge of the network, and when a query message periodically transmitted by the IP multicast router is transferred to a multicast group/source combination registered within the management table of the gateway switch, the gateway switch is configured to perform a function of: transmitting on behalf of mobile terminals belonging to the multicast group/source combination a report message in the multicast procedure to the IP multicast router without transferring the query message to mobile terminals belonging to the multicast group/source combination.