Abstract: A method of establishing a connection between a second host and an application socket on a first host. The method utilizes the Host Identity Protocol (HIP). The method includes the steps of establishing either a new or a selected existing HIP Security Association between the first and second hosts; creating a new or selecting an existing Tube Association between the application socket and the Security Association; and forming an association for the connection between the application socket, the Security Association, and the Tube Association. This establishes a connection between the second host and the application socket on the first host through the Security Association and the Tube Association.

Abstract: A method is provided of using the Host Identity Protocol, HIP, to establish a connection between a second host (32) and an application socket (42) on a first host (30), comprising establishing a new or selecting an existing HIP Security Association (46) between the first and second hosts (30, 32), creating a new or selecting an existing Tube Association (44), identified by a Tube Identifier, between the application socket (42) and the Security Association (46), forming an association (43, 45) for the connection between the application socket (42), the Security Association (46) and the Tube Association (44), thereby establishing a connection between the second host (32) and the application socket (42) on the first host (30) through the Security Association (46) and Tube Association (44).

Abstract: A method of authorizing an Internet Protocol (IP) enabled mobile host 1 to access the Internet 2 via an wireless LAN, GSM, UMTS access network 3 comprises initially sending an IP access request from the mobile host 1 to an IP router 5 within the access network 3. In response to receipt of said access request at the IP router 5, an IP address routing prefix is sent from the IP router 5 to the mobile host 1. Electronic cash is then forwarded from the mobile host 1 to a control point 6 within the access network 3. The control point 6 confirms the authenticity and/or sufficiency of the electronic cash and, providing that confirmation is made, sends an authorization message to the IP router 5. The IP router 5 blocks the transmission of IP packets between the mobile host 1 and the Internet 2 prior to receipt of the authorization message and permits the passage of IP packets only after an authorization message has been received.