Abstract: The network monitoring tool comprises an input for receiving data about the performance of the network and a data processor for analysing the data in order to produce an output. The output is at least one of the identification of a fault in the network and the derivation of information about the capability of the network to supply the utility.

Abstract: A monitoring tool receiving a plurality of queries about the performance of a network, each query being a query about the performance of the network in a respective location. The tool groups queries that exhibit a predetermined spatial relationship with respect to one another. The locations of the queries in the group define a zone. If the number exceeds a threshold, then the zone warrants inspection and/or queries about network performance in the zone can be met with an indication that there appears to be a fault affecting the zone. Alternatively, the tool compares a plurality of stored areas, each area corresponding to a different time period and delimited by a boundary formed around the locations to which a plurality of network performance queries, in the respective time period, relate.