A method of optimising a network includes selecting an operating characteristic of a network to optimise; determining at least one operating parameter of network nodes within the network which affects the operating characteristic; selecting an optimisable network node from within the network; identifying a cluster of the network nodes whose operating characteristic is affected by a change in the at least one operating parameter of the optimisable network node; iteratively adjusting the at least one operating parameter of the optimisable network node; determining the operating characteristic of the cluster of the network nodes in response to that adjusted at least one operating parameter of the optimisable network node; and selecting that adjusted at least one operating parameter of the optimisable network node which improves the operating characteristic of the cluster of the network nodes.