A processing terminal, for example a PDA or laptop, includes one or more application-layer programs and a network broker. The network broker exposes currently-available network resources, such as network access points in-range of the terminal, to the applications layer. The network broker is also arranged to automatically establish network connections via the or each network access point and to acquire operating parameters indicative of the status and/or performance of the connections. The available bandwidth of a connection is one example of an operating parameter. Data subsequently sent to, or transmitted from, the application-layer programs is communicated over a selected one or more of the established connections in accordance with predefined connection rules indicating which connection is/are to be selected in dependence on the operating parameters. Access credentials for enabling the terminal automatically to access a network via a different access point can also be provided using an existing connection.