System and method for controlling transfer of a frame

A method to be executed by an upper-level device and a plurality of lower-level devices configured to communicate with the upper-level device, the method comprising:

• providing the upper-level device connected to a Layer 3 network through a gateway, with a first storage unit that stores information on a port connected to each of the plurality of lower-level devices in association with a group identifier identifying a terminal group including a plurality of terminals under control of the each lower-level device;
• causing the upper-level device:
• to identify, upon receiving a first frame whose destination information include information specific to the gateway, based on a first terminal identifier identifying a first terminal that is a destination of a packet within the first frame, a first group identifier identifying a first terminal group to which the first terminal belongs,
• to search the first storage unit for the first group identifier, and
• to transfer, when the first group identifier is found in the first storage unit, the first frame from a port that is associated with the first group identifier in the first storage unit;
• and
• providing the each lower-level device with a second storage unit that stores information on a port connected to each terminal belonging to a terminal group, a terminal identifier identifying the each terminal, and information specific to the each terminal, in association with each other;
• and
• causing the each lower-level device:
• to update, upon receiving the first frame, the destination information of the first frame by using information that is specific to the first terminal and stored in the second storage unit in association with the first terminal identifier, and
• to transfer the first frame having the updated destination information from a port whose information is stored in the second storage unit in association with the first terminal identifier.

An apparatus connected to a Layer 3 network through a gateway and configured to communicate with a plurality of lower-level devices, the apparatus comprising:

• a memory configured to store information on a port connected to each of the plurality of lower-level devices, in association with a group identifier identifying a terminal group including a plurality of terminals under control of the each lower-level device;
• and
• a processor coupled to the memory, the processor being configured to:
• identify, upon receiving a first frame whose destination information includes information specific to the gateway, based on a first terminal identifier identifying a first terminal that is a destination of a packet within the first frame, a first group identifier identifying a first terminal group to which the first terminal belongs, and to search the memory for the first group identifier, and
• transfer, when the first group identifier is found in the memory, the first frame from a port associated with the first group identifier to a first lower-level device controlling the first terminal group identified by the first group identifier so that the first lower-level device updates the destination information of the first frame by using information specific to the first terminal.