ferent network slices which use different virtual resources mapped onto different physical resources. The same QoS metrics can be applied to services in virtualized networks as applied to the same services in non-virtualized networks. However, different slices can be isolated regarding the QoS metrics (e.g. dedicated bandwidth, i.e. bitrate) or not. QoS isolation is traditionally provided in telecom networks by use of VPNs, which are based on tunnel- ing of IP packets between pairs of nodes within a network (or between networks at the interconnections), where each VPN carries a certain type of traffic (aggregated traffic of 3.7 QoS in Future Networks a given type such as voice, video, or data, or individual traffic such as traffic for a given corporation). However, QoS is always end-to-end. So, for a given flow (from terminal A to terminal B), the packets may travel via several networks on the path (the networks belonging to different administrative domains are autonomous by default), which can carry that traffic by using different network slices (i.e. different LINPs). A complete slice is composed of not only various network functions which are based on virtualization in the access networks or core networks, but also transport network resources assigned to have a complete end-to-end path. Overall, various ICT/telecom businesses in future networks require different QoS parameters, such as different values for throughput, delay, and losses. Certain services may need guaranteed throughput and very low delay (e.g. mission-critical services, such as control in real time of various transportation vehicles, as one example). For such services the transport networks need to provide QoS isolation and flexible network operation and management, and improve the network utilization among different ser- vices in different verticals (i.e. different business). So, traditionally QoS isolation in transport networks is provided by VPN technology, which can give physical network resource isolation across multiple network segments. H