Patent ID: 8688970

Claim:
A method for determining a trust relationship between a core network and an access network for a user equipment that attaches to the access network, wherein the core network comprises a gateway and a home agent of the user equipment, the method comprising the steps of: allocating a home IP address/IP prefix of the user equipment at the home agent of the user equipment, upon attaching to the access network, receiving by the user equipment an IP address/IP prefix, assigned to the user equipment by the access network, exchanging messages of a security tunnel establishment procedure, performed between the user equipment and the gateway, the messages including information on at least one of the IP address/IP prefix and the home IP address/IP prefix of the user equipment, and after the step of exchanging the messages of the security tunnel establishment procedure, comparing in the gateway or in the user equipment the IP address/IP prefix with the home IP address/IP prefix, and in case they coincide, determining the access network is trusted by the core network, and in case they do not coincide, determining the access network is not trusted by the core network.