Patent attributes
A virtual network is dynamically created when a relay communication system is constructed including a plurality of relay servers that communicate with each other. In the relay communication system, VLAN client terminals which define a VLAN group share VLAN group information. In addition, a VLAN session is established between the VLAN devices as activatable VLAN client terminals among the VLAN client terminals based on the VLAN group information, and the VLAN devices are allowed to share virtual address information created when the VLAN group is activated. Furthermore, if the VLAN group has already been activated when instructed to activate the VLAN group, a join-in-progress signal to the VLAN group is transmitted to a join-in-progress VLAN client terminal as a transmission source of the activation instruction, and a VLAN session is established that is related to the join-in-progress VLAN client terminal and has not been established yet.
