With the advent of various emerging network services in recent years, the current best-effort based internet infrastructure has increasingly struggled in providing comprehensive support for these applications. Despite the QoS (Quality of Services) frameworks proposed in the 1990's, such as Integrated Services (IntServ) and Differentiated Services (DiffServ), large-scale deployments have not been seen across the global internet until now, and this slow progress has significantly hindered the development of the relevant services. In addition, network resilience to failures has become another major concern by today's ISPs (Internet Service Providers), as QoS assurance to end-users may be severely impacted by various failures which are very common in operational networks today.