proaches. Also, required are mechanisms for handling non-technical issues of accountability, which includes ethical, legal, and governance aspects. Virtualization. This refers to having virtual resources (e.g. resource allocation to slices of the network infrastructure) and virtual infrastructures (e.g. dynamic creation of slices for different services), and programmability of virtual clouds (including network clouds, service clouds, and virtual infrastructures). Self-management capabilities. These include self-functionality mechanisms (in a given domain and cross-domain) as well as self-functional infrastructure and systems (self-adaptation and self-composition of resources, context awareness, automated auditing, with increased cost-effectiveness of the networks and systems). Service-enabling capabilities. This is targeted toward creation of service-aware networks, where networks can discover services and have self-negotiation and self-contraction capabilities regarding SLAs. Orchestration capabilities. These capabilities govern the integrated activities and per- formances of different systems of systems and dynamically adapt to the changing contextual information, and based on that optimize usage of the network resources (switches, routers, etc.) and service resources (e.g. servers, service cloud resources). The ITU-T has defined network slicing via the definition of LINPs [25], which may be considered as the trigger for further standardization of network virtualization. By 3.7 QoS in Future Networks ITU-T's definition [25], network virtualization is a technology that allows multiple virtual networks called LINPs to coexist on a single physical network infrastructure. Virtual resources are created over the physical objects in the given network, which includes (in IP networks) nodes such as switches, routers, servers, and end-user terminals. LINP can use virtual resources based on their programmability features, which are required with the aim of having the virtual networks. Regarding legacy end-users (e.g. resi