Dynamic external home agent assignment in mobile VPN

The paper presents dynamic external home agent (x-HA) assignment for mobile virtual private networks (VPNs). The proposed architecture is based on the IPsec-based VPN proposed by the IETF for mobile users. The IETF solution, however, leads to two problems: where the x-HA should be put; how the x-HA should be trusted. We propose to assign the x-HA dynamically so the handoff latency and end-to-end latency can be reduced significantly. Based on the Diameter Mobile IPv4 application, we also propose a technique such that the x-HA can be associated with the VPN securely. In addition, registrations with x-HA and internal HA (i-HA) are concurrently accomplished. The proposed technique is implemented in a mobile VPN testbed. Performance analysis based on empirical experiments is discussed.