Patent ID: 8463880

Claim:
A method, comprising implementing a tunnel in a layer-three network, said tunnel preserving an active Internet Protocol (IP) session between a client device and a first portal point corresponding to a first subnet of the layer-three network by way of a connection between the client device and a second portal point corresponding to a second subnet of the layer-three network, said tunnel enabling the client device to maintain an IP address allocated to the first subnet and assigned to the client device by the first subnet; examining a buffer of outgoing packets scheduled to be transmitted in the future to determine whether data is scheduled to transfer from the second portal point to the client device in the future; in response to determining that no data is scheduled to transfer from the second portal point to the client device in the future, removing the tunnel by: disconnecting the client device from the second portal point; deactivating the IP session between the client device and the first portal point such that the IP address allocated to the first subnet and assigned to the client device is released to the first subnet; reconnecting the client device to the second portal point; and activating a second IP session between the client device and the second portal point such that a second IP address allocated to the second subnet is assigned to the client device by the second subnet; wherein the tunnel is not removed in response to determining that data is scheduled to transfer from the second portal point to the client device in the future.