the same conditions. 7.8.2 QoS Evaluation Scenarios For QoS measurements on the IP network services there are different scenarios that can be applied. However, all of them can be grouped into two main types: QoS evaluation scenario at the national level (e.g. test server located at the local Inter- net eXchange Point); QoS evaluation scenario at the international level (test server located at an interna- tional IXP). In the QoS evaluation scenario at the national level, the position of the test server (used for the measurements) is at the local IXP while probes are installed at the end-user premises. These measurements can be done by the NRAs with or without explicit par- ticipation of the ISPs. With the scenario on the national level, the measurement path includes all links and network nodes from the customer terminal to the test server located at the local IXP (Figure 7.11). So, the test is started by the probes (as one end of the measured Internet connection) and targeted at the local IXP (as the other end of the Internet connection) when measuring/testing local KPIs (e.g. mean data rate, packet delay, losses). The evaluation scenario at the international level is similar to the evaluation scenario on the national level, with the main difference being the location of the test servers (Figure 7.11). In the international case the test server is typically located at an inter- national IXP (e.g. it may be located in another country). As usual, higher bandwidth available to the given Internet connection end-to-end results in better QoS and vice versa. The international QoS evaluation scenario provides possibility to NRAs to test international data KPIs (e.g. download/upload data rate, delay). The QoS evaluation of IP network services at the national and international levels allows comparison of QoS levels locally and globally. 7 Broadband QoS Parameters, KPIs, and Measurements Local test International test server server probe Local International (access and core Internet networks) QoS measurement tests on national 