Abstract: The present invention provides a method of transmitting data in a network of interconnectable end-user nodes comprising a source node, a recipient node and a plurality of further nodes, wherein each of the end-user nodes is executing an instance of a communication client application. The invention also provides corresponding method of receiving data, and corresponding computer programs and user terminals. The method of transmitting data comprises: comprising: the communication client of the source node receiving a command to transmit the data to the recipient node; the source node selecting from the plurality of further nodes at least one storage node to store the data from the source node before being retrieved by the recipient node; transmitting the data from the source node to the at least one storage node; and the source node providing a network identity for each of the at least one storage nodes to the recipient node.

Abstract: A method, system and program for transmitting different quality versions of a stream to end-user nodes of a network. The method comprises: for each of a plurality of possible combinations of versions of the stream to different consuming end-user nodes, evaluating a utility function for each of those consuming end-user nodes, the utility function being dependent on the version and defining a quantitative measure of end-user benefit that would be experienced at the respective end-user node by consumption of the respective version; for each of said plurality of possible combinations of versions of the stream over said routes, determining an overall utility value based on the respective evaluation of the utility functions of each of said plurality of consuming end-user nodes; and selecting a preferred combination of versions of the stream over said routes based on the overall utility values of the different possible combinations.

Abstract: A method of transmitting a data stream to end-user nodes of a network, and a corresponding communication system, program, and distribution system for distributing the program. The method comprises: for each of a plurality of possible combinations of routes of the stream to a plurality of consuming end-user nodes, evaluating a utility function for each of the consuming end-user nodes, the utility function being dependent on route and defining a quantitative measure of end-user benefit that would be experienced at the respective end-user node by consumption of the stream; for each of the plurality of possible combinations of routes, determining an overall utility value based on the respective evaluation of the utility functions of each of the plurality of consuming end-user nodes; and selecting a preferred combination of routes for the stream based on the overall utility values of the different possible combinations.

Abstract: A method, system and program for routing a data stream amongst a plurality of network nodes including at least a plurality of end-user nodes. The method comprises: establishing a plurality of routes for the stream to a plurality of consuming end-user nodes, including at least one route via one or more relaying nodes; at each of a plurality of optimising nodes, executing an optimisation algorithm to determine a respective routing modification by evaluating a routing criterion with respect to a collection of end-user nodes which share information with the respective optimising node and determining a change in the routing criterion that would result from one or more potential routing modifications. The different optimising nodes' collections of end-user nodes are at least partially coincident such that each optimising node can determine a different routing modification with respect to at least some of the same end-user nodes.

Abstract: A method of providing services in a communication system. The method comprises: establishing a call instance from a caller terminal to a service provider terminal in the communication system; transmitting from the service provider terminal a service proposal in the form of an electronic document via the established call instance to the caller terminal; selectively accepting or rejecting the service proposal at the caller terminal; and in the case of acceptance of the service proposal, transmitting a request for money to a backend server in the communication system from the caller terminal; transmitting electronic cash tokens from the backend server to the caller terminal in response to the request to receive money; forwarding the electronic cash tokens from the caller terminal to the service provider terminal, whereafter the service provider provides services in accordance with the service proposal.