Abstract
This thesis presents the 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 questions: where should we put the x-HA and how should we trust the x-HA? We propose to assign the x-HA dynamically so the handoff latency and end-to-end latency could be reduced significantly. Based on Diameter Mobile IPv4 application, we also propose a technique such that the x-HA can be associated with the VPN securely. In addition, the 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.