There is described a method for optimising the distribution of data objects between caches in a cache domain of a resource limited network. User requests for data objects are received at caches in the cache domain. A notification is sent from each cache at which a request is received to a cache manager. The notification reports the user request and identifies the requested data object. At the cache manager, object information including the request frequency of each requested data object and the locations of the caches at which the requests were received is collated and stored. At the cache manager, objects for distribution within the cache domain are identified on the basis of the object information. Instructions are sent from the cache manager to the caches to distribute data objects stored in those caches between themselves. The objects are classified into classes according to popularity, the classes including a high popularity class comprising objects which should be distributed to all caches in the cache domain, a medium popularity class comprising objects which should be distributed to a subset of the caches in the cache domain, and a low popularity class comprising objects which should not be distributed.