Abstract: A computer network comprises a plurality of hosts and a plurality of hubs, in which each host can communicate with a hub through a connection service using one or more host protocols. Each hub executes a relay service to exchange data with at least one other hub using a hub protocol, in which network a service controller operates to determine dynamically which hub executes a service in response to a request form a service from a host. Thus, the network is not dependent upon the operation of a single hub; and the service controller can cause a connection service to operate on a selected one of a plurality of hubs in dependence upon loading and/or availability.