 can be offered to end-users to foster penetration of broadband/ultra-broadband access on a national basis because it is of significant importance to society (e.g. for the development of the single digital market), not only a part of the market "battle" (for customers) between national telecom operators. 9.5 Specifying Parameters, Levels, and Measurement Methods QoS regulation is directly related to specification of QoS parameters, their targets, and measurement methods. QoS measurement methodology should be established in such a manner to be able to provide estimation of the given set of QoS metrics. Regarding measurements in the 2010s and the 2020s, they are almost all on IP-based networks which have either fixed or mobile broadband access (in the 2010s) or ultra-broadband access (in the 2020s). IP-based networking is based on use of TCP or 9 QoS Regulatory Framework UDP as the main transport protocols between the IP (IPv4 or IPv6) on the network layer and the application on the top. In that regard TCP is always based on duplex connection because TCP segments travel from node A to node B and acknowledgements (ACKs) travel in the opposite direction (from node B to node A). Also, the Internet is based on a client server paradigm (in both networking cases, TCP/IP or UDP/IP) where the client sends a request (from the client application) to the server (to the server application) and receives a response from the server (e.g. with the requested data, such as a Web page with its content, video stream, audio stream, etc.). However, outbound and inbound traffic paths (or routes) may differ, SO any measurements at the intermediate network nodes (i.e. routers, gateways) may practically cover only one way of the service. Such an approach refers to passive measurements in the network by monitoring (for measurement purposes) user traffic. For such reasons, QoS is assessed mainly by active measurements where the measurement points are in fact on one of the communication endpoints (e.g. client or server side of the application)