Patent ID: 8244857

Claim:
A computer network comprising a plurality of devices interconnected via communication links, each of said devices having access to quality of service data indicating the quality of service provided by said plurality of devices, each of said devices being arranged in operation to respond to a service request by: selecting one of said other devices to provide the requested service; requesting the selected device to provide said service; monitoring the quality of service provided in response to said request; updating said quality of service data in response to said monitored quality of service; wherein said provider selection comprises selecting between a first provider selection mode using said quality of service data in order to select one or more favored service providers which have recently provided a relatively high quality of service, and a second provider selection mode in which a service provider is selected probabilistically from the available service providers without favoring service providers which, according to said quality of service data, have recently provided a relatively high quality of service; said mode selection comprising: retrieving an average measure of the quality of service achieved when said second mode of selection has been used to select a service provider; comparing said average second-mode quality-of-service measure and said quality of service data relating to said favored service providers; selecting said second mode of service selection with a probability which increases on said comparison indicating that said second mode is likely to select service providers offering better quality of service than said favored service providers; and on said second mode of selection being used to select a service provider, updating said average second-mode quality-of-service measure in response to said monitored quality of service.