A method for monitoring the performance of a plurality of wireless networks created by a plurality of wireless access points, comprising, by means of a management server: receiving performance data from the plurality of wireless access points; analysing the performance data to identify any wireless access points which are experiencing wireless network performance degradation; identifying the location of each wireless access point; grouping by regions of location the wireless access points which are experiencing wireless network performance degradation; and for each group, determining the cause of the wireless network performance degradation, characterised in that : the received performance data comprise: for each wireless access point, a set of IP Flow records generated by the plurality of wireless access points, each IP flow record corresponding to a data session between a client device and a remote resource via a wireless local area network of the wireless access point, and associated performance statistics; and WAN performance metrics indicative of the performance of a WAN link between each wireless access point and an Internet Service Provider; and a wireless access point in the plurality of wireless access points is identified as experiencing wireless network performance degradation when: the performance statistics for each associated IP Flow record of that wireless access point indicates degradation of performance of the wireless local area network; and the WAN performance metrics associated with that wireless access point do not indicate degradation of the WAN link. receiving performance data from the plurality of wireless access points; analysing the performance data to identify any wireless access points which are experiencing wireless network performance degradation; identifying the location of each wireless access point; grouping by regions of location the wireless access points which are experiencing wireless network performance degradation; and for each group, determining the cause of the wireless network performance degradation, the received performance data comprise: for each wireless access point, a set of IP Flow records generated by the plurality of wireless access points, each IP flow record corresponding to a data session between a client device and a remote resource via a wireless local area network of the wireless access point, and associated performance statistics; and WAN performance metrics indicative of the performance of a WAN link between each wireless access point and an Internet Service Provider; and for each wireless access point, a set of IP Flow records generated by the plurality of wireless access points, each IP flow record corresponding to a data session between a client device and a remote resource via a wireless local area network of the wireless access point, and associated performance statistics; and WAN performance metrics indicative of the performance of a WAN link between each wireless access point and an Internet Service Provider; and a wireless access point in the plurality of wireless access points is identified as experiencing wireless network performance degradation when: the performance statistics for each associated IP Flow record of that wireless access point indicates degradation of performance of the wireless local area network; and the WAN performance metrics associated with that wireless access point do not indicate degradation of the WAN link. the performance statistics for each associated IP Flow record of that wireless access point indicates degradation of performance of the wireless local area network; and the WAN performance metrics associated with that wireless access point do not indicate degradation of the WAN link. <EOS>