Patent ID: 7477626
Filing Date: 2009-01-13
Classification: H04L,H04W

Abstract:
1. A method of dynamically assigning external home agent (x-HA) for mobile Virtual Private Networks (VPNs), the method establishing VPN between at least one external network and an internal network and enabling at least one mobile node (MN) to roam in the external networks with security, the method comprising the steps of: a Dynamic Host Configuration Protocol (DHCP) server allocating a Care Of Address (CoA) to the MN and the MN sending a Registration Request (Reg-Req) message to an external home agent (x-HA) when the MN roams to the external network for the first time, wherein the Reg-Req message comprises fields including a home address (HoA) request, and a home agent (HA) address request; the x-HA sending an AA-Mobile-Node-Request (AMR) message to a foreign authentication, authorization and accounting (AAAF) server, the AAAF server filling the Network Access Identifier (NAI) of a candidate x-HA in AMR message and sending the AMR message to a home authentication, authorization and accounting (AAAH) server acting as an agent assignor; the AAAH server establishing security associations (SAs) among the candidate x-HA and the MN and generating a Home-Agent-Mobile Internet Protocol Request (Home-Agent-MIP-Request) (HAR) message for sending to the x-HA; the x-HA allocating an external home address (x-HoA) for the MN and filling the x-HoA and its x-HA address thereof in the Home-Agent-MIP-Answer (HAA) message, the x-HA then sending the HAA message to the AAAH server; the AANH server using a pre-configured Virtual Private Network-Tunnel Inner Address (VPN-TIA) as an internal CoA of the MN for registration to an internal-Home Agent (i-HA), the i-HA authorizing the AAAH server to send an AA-Mobile-Node-Answer (AMA) message to the x-HA; and the x-HA obtaining a Reg-Reply message sent from the AMA message and containing the allocated x-HoA and the x-HA address, and then sending the Reg-Reply message to the MN; when the MN roams in the external network, the MN uses the x-HoA for registration to the assigned x-HA with the x-HA address.