Abstract: In a communication system including a MN, a MFA connected to the MN, and a HA connected to a home network of the MN, the HA holds a layer 3 address of the HA and a source layer 3 address of a registration request by associating them with each other. The MFA transmits a layer 2 frame from the MN to the HA by encapsulating it. The HA decapsulates the frame to transmit it to the home network. When the HA receives a layer 2 frame from the home network, the HA checks that the destination layer 3 address is registered, and encapsulates the layer 2 frame to transmit it to a source layer 3 address of the registration request that is registered being associated with the destination layer 3 address. The MFA decapsulate the encapsulated layer 2 frame to transmit the layer 2 frame to the MN.

Abstract: In a communication system including a MN, a MFA connected to the MN, and a HA connected to a home network of the MN, the HA holds a layer 3 address of the HA and a source layer 3 address of a registration request by associating them with each other. The MFA transmits a layer 2 frame from the MN to the HA by encapsulating it. The HA decapsulates the frame to transmit it to the home network. When the HA receives a layer 2 frame from the home network, the HA checks that the destination layer 3 address is registered, and encapsulates the layer 2 frame to transmit it to a source layer 3 address of the registration request that is registered being associated with the destination layer 3 address. The MFA decapsulate the encapsulated layer 2 frame to transmit the layer 2 frame to the MN.