A method of analysing network performance of a network comprising a plurality of network nodes (30, 30a, 30b), the method comprising: obtaining, in respect of a first target node, a plurality of probe measurements, the probe measurements in respect of the first target node including: - at least one probe measurement resulting from one or more probe test-messages being sent via a network path from a testing node to said first target node and one or more associated probe response-messages triggered by receipt and local processing at said first target node of the one or more probe test-messages being received via a network path from the first target node by the testing node; and - at least one probe measurement resulting from one or more probe test-messages being sent via a network path from a testing node via the first target node to a subsequent target node and one or more associated probe response-messages triggered by receipt and local processing at said subsequent target node of the one or more probe test-messages being received via a network path from the subsequent target node by the testing node; the respective probe measurements each relating to one or more network performance characteristics in respect of the network paths taken by the respective probe test-messages and the probe response-messages associated therewith and being dependent also on the local processing of the respective probe test-messages at the respective target nodes; and comparing at least one of said one or more probe measurements resulting from one or more probe test-messages being sent to said first target node with at least one of said one or more probe measurements resulting from one or more probe test-messages being sent via the first target node to a subsequent target node; characterised in that the method further comprises assigning a weighting in respect of at least one of said target nodes in dependence on the comparison; and determining a network performance analysis measure according to a predetermined function dependent on at least one probe measurement in respect of at least one of said target nodes and on the weighting assigned in respect of said at least one target node. obtaining, in respect of a first target node, a plurality of probe measurements, the probe measurements in respect of the first target node including: - at least one probe measurement resulting from one or more probe test-messages being sent via a network path from a testing node to said first target node and one or more associated probe response-messages triggered by receipt and local processing at said first target node of the one or more probe test-messages being received via a network path from the first target node by the testing node; and - at least one probe measurement resulting from one or more probe test-messages being sent via a network path from a testing node via the first target node to a subsequent target node and one or more associated probe response-messages triggered by receipt and local processing at said subsequent target node of the one or more probe test-messages being received via a network path from the subsequent target node by the testing node; the respective probe measurements each relating to one or more network performance characteristics in respect of the network paths taken by the respective probe test-messages and the probe response-messages associated therewith and being dependent also on the local processing of the respective probe test-messages at the respective target nodes; and - at least one probe measurement resulting from one or more probe test-messages being sent via a network path from a testing node to said first target node and one or more associated probe response-messages triggered by receipt and local processing at said first target node of the one or more probe test-messages being received via a network path from the first target node by the testing node; and - at least one probe measurement resulting from one or more probe test-messages being sent via a network path from a testing node via the first target node to a subsequent target node and one or more associated probe response-messages triggered by receipt and local processing at said subsequent target node of the one or more probe test-messages being received via a network path from the subsequent target node by the testing node; comparing at least one of said one or more probe measurements resulting from one or more probe test-messages being sent to said first target node with at least one of said one or more probe measurements resulting from one or more probe test-messages being sent via the first target node to a subsequent target node; characterised in that the method further comprises assigning a weighting in respect of at least one of said target nodes in dependence on the comparison; and determining a network performance analysis measure according to a predetermined function dependent on at least one probe measurement in respect of at least one of said target nodes and on the weighting assigned in respect of said at least one target node.