Guest Editors' Introduction: Special Issue on Efficient Management of SDN/NFV-Based Systems - Part I

CURRENTLY, there is a lot of interest in both industry and academia in the softwarization of telecommunication networks. This evolution is enabled by three paradigms, which are synergetic and reinforce each other. First, Software-Defined Networking (SDN) allows network control to be separated from the forwarding plane and allows for a flexible management of the network resources. Leading equipment providers in the network infrastructure market launched the first SDN-enabled appliances. Second, Network Virtualization (NV) brings virtualization concepts to the network, similar to cloud computing, which was enabled by virtualization of servers. The first products offering network virtualization capabilities are already available on the market. Third, Network Function Virtualization (NFV) focuses on virtua-lization of software-based network functions. Classical exam-ples include virtualization of home gateways, firewalls, set top boxes, deep packet inspection components, IMS components, and monitoring probes. Instead of installing and managing dedicated hardware devices for these functions, they are instead implemented as software components and deployed on commodity hardware infrastructures, in most cases operated by a network operator and referred to as telco clouds. Service Function Chaining (SFC) consists of building services using virtual network functions (VNFs). The main reasons for network operators to adopt the above principles of network softwarization are: (i) faster and easier deployment, configuration, and updating of network functions, (ii) maximization of resource utilization when using commodity hardware and software-based functions, and (iii) it enabling of a Network-as-a-Service business model. From the point-of-view of service providers, the main benefits include: (i) dynamic scaling of resources based on service requirements