5G technologies are a new paradigm strongly supported by the European Commission (EC) to overcome the challenges of next generation networks and aiming to tackle the novel and manifold business requirements of vertical sectors such as Industry 4.0, Smart Grids, Smart Cities, and eHealth. Extraordinarily high speeds and capacity, multi-tenancy, fixed and wireless access network convergence, self-X, unconventional resource virtualisation, on-demand service-oriented resource allocation and automated management of resources are only few examples of the complex demands that 5G aims to undertake. The accommodation of such features requires multipronged efforts in different network technology domains at various levels. In this paper, we investigate how the relative 5G network features challenge the current generation of access networks, both fixed and wireless, and data centres, from an end-to-end network service point of view. Furthermore, we provide some insights into how emerging technologies such as Network Function Virtualisation (NFV) and Software Defined Networks (SDN) can be utilized for the accommodation of the above mentioned features and realization of 5G networks.