A method of analysing network performance of a network comprising a plurality of network nodes, the method comprising: obtaining a plurality of probe measurements, the probe measurements including: - at least a first probe measurement resulting from one or more probe test-messages being sent from a first node and having a second node as a target node thereof, said probe test-messages being sent via a network path to said second node and one or more associated probe response-messages triggered by receipt and local processing at said second node of the one or more probe test-messages being received via a network path from the second node by the first node; and - at least a second probe measurement resulting from one or more probe test-messages being sent from the second node and having the first node as a target node thereof, said probe test-messages being sent via a network path to said first node and one or more associated probe response-messages triggered by receipt and local processing at said first node of the one or more probe test-messages being received via a network path from the first node by the second 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 first probe measurement with at least one second probe measurement; characterised in that the method further comprises assigning a weighting in respect of at least one of said first and second nodes in dependence on the comparison; and determining a network performance analysis measure according to a predetermined function dependent on at least one of said probe measurements and in dependence on the weighting assigned in respect of said at least one node. obtaining a plurality of probe measurements, the probe measurements including: - at least a first probe measurement resulting from one or more probe test-messages being sent from a first node and having a second node as a target node thereof, said probe test-messages being sent via a network path to said second node and one or more associated probe response-messages triggered by receipt and local processing at said second node of the one or more probe test-messages being received via a network path from the second node by the first node; and - at least a second probe measurement resulting from one or more probe test-messages being sent from the second node and having the first node as a target node thereof, said probe test-messages being sent via a network path to said first node and one or more associated probe response-messages triggered by receipt and local processing at said first node of the one or more probe test-messages being received via a network path from the first node by the second 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 a first probe measurement resulting from one or more probe test-messages being sent from a first node and having a second node as a target node thereof, said probe test-messages being sent via a network path to said second node and one or more associated probe response-messages triggered by receipt and local processing at said second node of the one or more probe test-messages being received via a network path from the second node by the first node; and - at least a second probe measurement resulting from one or more probe test-messages being sent from the second node and having the first node as a target node thereof, said probe test-messages being sent via a network path to said first node and one or more associated probe response-messages triggered by receipt and local processing at said first node of the one or more probe test-messages being received via a network path from the first node by the second 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 first probe measurement with at least one second probe measurement; characterised in that the method further comprises assigning a weighting in respect of at least one of said first and second nodes in dependence on the comparison; and determining a network performance analysis measure according to a predetermined function dependent on at least one of said probe measurements and in dependence on the weighting assigned in respect of said at least one node.