1. A method of configuring a set of network elements, comprising: selecting the set of network elements, determining, by a machine, a configuration parameter for each network element in the set; measuring a performance parameter dependent upon said configuration parameter for each selected network element; and selectively adjusting, by the machine, the configuration parameter of at least one network element in dependence on the measured performance parameter for said network elements in the set, wherein the configuration parameter of the at least one network element is adjusted responsive to a value of the measured performance parameter of the at least one network element being a threshold less than a value of the measured performance value of at least one further network element.