e driven largely by a user-centric model of service provisioning, where the end user is responsible for producing most of the content or the inherent value of these services. For example, Facebook had more than 390 million users that were adding 2 billion photos and 14 million videos every month by October 2009 [1]. This emerging generation of services, named the Web 2.0 generation, relies on content that is gen- erated by the end user as well as enabling third-party application developers to act as service providers. Facebook has more than 350 thousand applications developed by more than 1 million developers [1]. These Internet services are being provided "over the top," that is, they do not rely on the network operator beyond providing access to the Internet. Free VoIP services on the Internet are eroding the operators voice revenues and the so-called Internet "App Stores" are allowing mobile develop- ers to completely bypass the network operators' walled gardens. End users can now buy applications to use on their phones without paying the network operator (beyond the existing connectivity fees). In 2007, the network carriers' portal Web sites were visited by 57% of all UK mobile Internet users. By 2008, the figure dropped to 22% as users turn to other sources for their mobile content and services [1]. Network operators have recognized the challenges presented by the Web 2.0 revolution, and have begun the transition toward Service Delivery Platforms (SDPs). These SDPs are designed to allow the rapid prototyping of new and innovative ser- vices that can take advantage of the higher bandwidth available on the current access networks, as well as the enriched multimedia capabilities of today's telecom- munication devices. It is hoped that these SDPs will allow the network operator and third-party developers the opportunity to provide a myriad of new services, open- ing up new revenue streams and increasing the Average Revenue Per User (ARPU). These SDPs are largely based on top of a Next Generation Network (NGN), w