Guest editorial: Network and service virtualization

The introduction of software-defined networking (SDN) and network function virtualization (NFV) has altered, in a wholesale manner, the way to plan for network infrastructure evolution in the forthcoming decade. This Feature Topic aims to provide a concise reference entry point to a wider audience with respect to carrier-grade networking and service virtualization with emphasis on automating the entire networking and cloud infrastructure. The first steps in network virtualization are already taking place today, although more often than not through a piecemeal approach that simply replaces hardware-based network appliances with software-based alternatives. This may help to reduce operator costs in the mid-term but does not alter the full life cycle of service creation and deployment. The real potential for network and service virtualization lies in upgrading the entire toolbox network operators have at their disposal, as state-of-the-art research and development efforts already indicate. For example, the European FP7 UNIFY project defines an architecture where the entire network, from home devices to data centers, forms a unified production environment, a dynamic service creation platform able to distribute functions and state anywhere in the network, aided by automated orchestration engines; see www.fp7-unify.eu for more details. While drafting the Call for Papers for this Feature Topic, our first goal was to attract high-quality contributions from operator and industry research labs as this topic is particularly pertinent to practitioners in the field. Carriers, in particular, can be the main beneficiaries from the emerging infrastructures based on NFV, SDN, and cloud technologies. Therefore, articles by authors working at global operators currently developing, evaluating, and standardizing solutions for network and service virtualization were particularly welcome and encouraged. In this sense, we are glad that all five selected papers for publication in this issu- are penned by experts affiliated with European, American, and Asian carriers.