e the integrity of the results (e.g. during their storage or trans- mission from a probe station to a centralized database). Openness. This refers to availability of details about the measurement (e.g. open source code). However, the quality measurement system should be preferably based on specifications, standards, recommendations as well as best practices. Future-proof. The measurement system should have flexibility, be extensible and scal- able (e.g. regarding introduction of new test scenarios). In this manner the system will also be more cost-effective. The QoS/QoE measurement systems can be based on either software applications (that can be downloaded and installed on end-users' devices such as computers and smartphones) or dedicated probe stations/nodes which are deployed on the side of the network provider or the customer's network. In all cases the QoS measurement system can be based on two following measurement methods [20, 21]: Passive measurement method. This type of measurements is based on observation of user data packets on a network link in a non-intrusive manner (e.g. moni- toring/sniffing regular IP packets that carry user data, control or management information, and their statistical processing afterwards for calculation of various QoS parameters such as average or maximum bitrate, packet delay, or jitter, etc., which can be per type of service, per flow, and SO forth). However, the drawback is that this may result in significant processing load of network nodes or requirement for large storage (on disks) of the collected data, which increases significantly with availability of ultra-broadband access. Therefore, purely passive measurement method is unlikely to be used for estimation of QoS metrics such as KPIs in nowadays broadband and ultra-broadband networks. However, passive measurements may be also based on test packets (e.g. marked IP packets, in the IP payload) sent from the QoS measurement systems, which are passively monitored by the network nodes and further used for statistical calcul