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Network functions virtualization (NFV) is consolidating as one of the base technologies for the design, deployment, and operation of network services. NFV can be seen as a natural evolution of the trend to cloud technologies in IT, and hence perceived as bringing them to the network provider environments. While this can be true for the simplest cases, focused on the IT services network providers rely on, the nature of network services raises unique requirements on the overall virtualization process. NFV aims to provide at the same time an opportunity to network providers, not only in reducing operational costs but also in bringing the promise of easing the development and activation of new services, thereby reducing their time-to-market and opening new approaches for service provisioning and operation, in general. In this chapter, the authors analyse these requirements and opportunities, reviewing the state of the art in this new way of dealing with network services. Also, the chapter presents some NFV deployments endorsed by some network operators and identifies some remaining challenges.

Network Functions Virtualization (NFV) has emerged as a new paradigm for designing, deploying and operating network services. It is a natural evolution of the current trend of applying cloud technologies to Information Technology (IT) services, bringing them to network provider environments. While this is true for the most simple use cases, focused on the IT services network providers rely on, the nature of network services and the physical anchors of network themselves impose additional, unique requirements on the virtualization process in this environment. At the same time, NFV provides an opportunity to network providers, reducing operational costs and bringing the promise of dramatically easing the development of new services, reducing their time-to-market, and opening new possibilities for service provisioning. This chapter analyses these requirements and opportunities and the challenges NFV brings to network providers, and reviews the current state of the art in this new way of dealing with network services.

Videoconferencing and multimedia communication technologies in general are gaining momentum with the development of networked organizations. Efforts are currently underway to further adapt multimedia technologies to virtual organizations where multimedia communications find applications in training and education, customer relationships management, enterprise resource planning and many other areas (Camarinha-Matos, 2002).

The Internet and, more specifically, Web-based applications now provide the first-ever global, easy-to-use, ubiquitous and economical communications channel. Most companies have already automated their operations to some extent, which enhances their ability to interact with other companies electronically. With the advent of Web services, the interaction between companies becomes easier and more transparent (Khalaf, Curbera, Nagy, Tai, Mukhi, & Duftler, 2005). Web-based technologies are extensively employed and support core components of virtual and networked organizations. Many of them, including for instance Web-based communities, heavily rely on Web traffic. Additionally, Web technologies play a central role in the technologies for supporting industrial virtual enterprises (VE) being developed by the National Industrial Information Infrastructure Protocols Consortium (NIIIP). Thus, modelling and analysis techniques for Web traffic become important tools for performance analysis of virtual organizations (Malhotra, 2000; Foster, Kesselman, & Tuecke, 2001). This article overviews current models of Web traffic as well as performance analysis of Web-based systems.

In this article, general findings about Internet traffic models are first reviewed, with emphasis on two important invariants or characteristics that are observed with some reproducibility and independently of the precise settings of the network under consideration: self-similarity and heavy-tail marginal distributions. Then metrics and measurement techniques and tools will be discussed. This article deals with generic network performance measurement systems and outlines models, measurement techniques and tools that measure performance at the network and transport layers and can thus be applied regardless of the application layer protocols being employed. These systems are useful for analyzing performance of any network application and are an important foundational tool for enabling advanced virtual organizations (Foster, Kesselman, & Tuecke, 2001). Note, however, that application-level (or specific application details aware) measurements are commonly needed to complement generic tools so as to achieve a clear understanding of overall applications performance, which cannot be synthesized from lower level data with ease (Andrews, Cao, & McGowan, 2006).