Patent ID: 7954141

Claim:
A method for authenticating a subscriber of a first network to access an application service through a second network, wherein the second network is a packet data network and the access to the application services is in the form of access-request messages enclosed in a data packet, said data packet comprising an address in said second network allocated to a subscriber's address and said access-request message expressed with a syntax that complies with an application-level protocol, comprising the steps of: a) intercepting an access-request message to the second network; b) recognising the application-level protocol; c) providing a mapping between the subscriber's address and a first subscriber's identifier in the first network; d) generating a first authentication token including a second subscriber's identifier; e) associating the first authentication token to the access-request message; and f) transmitting the access-request message with said first associated authentication token to the second network.