Abstract: A method of delivering streaming data to a user device comprises delivering a first data stream supplied by a data server to a user device via a router, and receiving a change request from the user device, the change request being indicative of a second data stream required by the user device. A data server having the second data stream available for delivery to the router is identified, and the second data stream is delivered from the identified data server to the router. Delivery of the first data stream to the user device is ceased, and, after such cessation of delivery of the first data stream, delivery of the second data stream to the user device commences.

Abstract: The invention relates to a method, computational devices, a system of computational devices and computer program products for abstracting address and port number usage for an application running on first and second devices. The system comprises a first device (10) that receives a request for binding of a socket to a service from the application in said first device, obtains a service name, generates a resource record (26) comprising a binding between a port number and the service name, creates a socket and binds it to the port number, and sends the record to a resolving unit (22) associated with the first device, and a second device (16) that receives a request for a connection from the application in said second device, sends a query regarding the service name to the resolving unit, and receives an address and port number associated with the first device as response to the query.

Abstract: An access is requested by a local host to a public network. A public address to be used for the access to the public network is determined. A local address, corresponding to the local host, is mapped to the public address. The public address is returned to the local host. A determination is made as to whether an outbound access is to a local network or a public network. When the outbound access is to a public network, then an access is requested to the public network. Public information in response to the request is received. The public information is placed in a payload portion of one or more packets created for the outbound access. The public information generally comprises at least a public port, but may also comprise a public address. The request may supply a local port, so that a public port in the public information will generally conform to the local port.