Patent ID: 8817683
Filing Date: 2014-08-26
Classification: H04L

Abstract:
1. A network relay apparatus constructed to relay a multicast packet between plural logically different virtual networks, the network relay apparatus comprising: a first management module configured to manage communications of a first virtual network; a second management module configured to manage communications of a second virtual network; and an intra-device relay module configured to relay the multicast packet for a preset multicast group between the first management module and the second management module, the first management module having: a transmission apparatus information acquisition module configured to generate a join message for joining the preset multicast group, and to send the join message toward a transmission apparatus in the first virtual network, and to acquire, from the first virtual network, transmission apparatus information used for identifying the transmission apparatus in the first virtual network in response to the join message; a first communication route establishment module configured to refer to the acquired transmission apparatus information, and to establish a communication route of the first virtual network between the transmission apparatus in the first virtual network and the first management module on the basis of the acquired transmission apparatus information; and a transfer module configured to transfer a multicast packet, which is received from the transmission apparatus via the established communication route, to the intra-device relay module, the second management module having: a multicast packet receiving module configured to receive the multicast packet from the intra-device relay module; and a multicast packet transmission module configured to send the received multicast packet to a receiving apparatus in the second virtual network, which makes a request for receiving the multicast packet from the first virtual network, the intra-device relay module having: a relay information storage module configured to store a relay condition for the multicast packet for the preset multicast group to be relayed from the first management module to the second management module; and an intra-device transmission module configured to control the multicast packet to be relayed from the first management module to the second management module, based on the stored relay condition, and wherein the transmission apparatus information acquisition module in the first management module sends the join message to the first virtual network at preset time intervals, in order to acquire the transmission apparatus information, the relay condition is set to assign the first management module as a sender and the second management module as a receiver for inter-network relay of the multicast packet for the preset multicast group, the intra-device transmission module in the intra-device relay module relays the multicast packet from the first management module to the second management module based on the relay condition, wherein in response to reception of a join request for the preset multicast group from the receiving apparatus in the second virtual network, the second management module sends a request for transmission of a join message to the transmission apparatus information acquisition module in the first management module via the intra-device relay module, the transmission apparatus information acquisition module receives the request for transmission of the join request from the intra-device relay module and sends the join request to the first virtual network, and the network relay apparatus further comprising: a relay information generation module configured, when a join message for the preset multicast group is received from the receiving apparatus in the second virtual network, to assign the second management module as the receiver in the relay condition, and when the multicast packet is received from the transmission apparatus in the first virtual network as a response to transmission of the join request for the preset multicast group, to additionally assign the first management module as the sender in the relay condition.