Can high quality be provided economically for all transmissions on the Internet? Current work assumes that it cannot, and concentrates on providing differentiated service levels. However, an examination of patterns of use and economics of data networks suggests that providing enough bandwidth for uniformly high quality transmission may be practical. If this turns out not to be possible, only the simplest schemes that require minimal involvement by end users and network administrators are likely to be accepted. On the other hand, there are substantial inefficiencies in the current data networks, inefficiencies that can be alleviated even without complicated pricing or network engineering systems.

Multimedia communication has gained increasing attention, both from the application side and the network provider side. While resource provisioning for QoS support in packet switched networks has lead to the design and development of sophisticated QoS architectures, notably ATM, IntServ or DiffServ, research has not exactly been user or application-context centered. In the cause of the evolution of QoS architectures, the integrated service network approach has lost momentum, and with it, the notion of QoS guarantees. Differentiation of QoS classes within the DiffServ framework is based on the definition of various per-hop behaviors. What is currently missing is a technique for specification and mapping of application and user QoS preferences onto evolving service profiles. In addition, adaptation of applications (and users) is becoming increasingly important in the face of dominating weak QoS-assurance paradigms, both in wireline and wireless environments. As a prerequisite, this paper...