re prerequisites to access any application/content transferred over the Internet (e.g. DHCP is essential for allocation of an IP address to the network interface of the user device, while DNS is crucial for mapping the domain names used by end-users into IP addresses which are used for delivery of the IP packets from a given source to a given destination). Assuming that the IAS is available and considering the fact that 2/3 of the total Internet traffic is video (i.e. media streaming) and its most important KPI is data transmission speed, the straightforward conclusion is that the most important KPI for data services is data transmission speed (i.e. bitrates in downlink and uplink directions). One should note that the delay is also influenced by the bitrates. For example, the transmission delay for transfer of 2 MB with 160 Kbit/s 7.5 KPIs for Data Services and VPNs will be bits/160 X 103 bit/s = 100 seconds, while for bitrate of 160 Mbit/s the transmission time delay for the same 2 MB will be 0.1 seconds. So, the KPIs are not independent from each other; however, the bitrate (i.e. data rate) is the most important one (after the availability of broadband IAS). Therefore deployment of ultra-broadband access and transport networks for data services (i.e. for IAS) has crucial importance for further development of data services and for development of digital society based on various data services (provide over IAS). Considering the above discussion, when the IAS is available, then the most important KPIs will be: Data transmission rate (i.e. bandwidth). That is the maximum number of bits that a given transmission path can carry. Each end-to-end path consists of many links which may have different bandwidth and different capacity for the given data service travers- ing that link (flow bitrate is normally below the link capacity). Then, the link with the lowest transmission data rate on the path is called bottleneck link and it defines the end-to-end transmission rate for the given service stream (e.g. media stream). P