Network support for application-oriented QoS

Addresses a dilemma raised by recent advances in networking technology, which provide support both for a rich variety of qualities of service (QoSs) and for applications that connect many end-points. Together these features encourage the development of complex multi-party applications that use a diverse set of data types. This raises a two-fold problem: how do application designers choose and specify the many QoS parameters that drive the ultimate performance of their applications; and how does the network efficiently manage its resources to support such a rich application mix? Our approach to this problem is to allow applications to be built around value-added services that encapsulate a variety of simpler resources. This enables both the specification of QoS in terms meaningful to applications, and global optimization of resource allocation across multiple streams and data types. We present a network architecture and a preliminary implementation that explicitly support the notion of application-oriented QoS for complex network services. The key concept is that of service brokers, which applications and service providers use to identify the network resources needed to meet QoS and cost objectives. Service brokers can incorporate a detailed understanding of an application domain, allowing them to make intelligent tradeoffs and to interact with applications and service providers at a high level. They can be hierarchical, in the sense that one broker can invoke the services of another broker. Finally, they provide the ability to deal with heterogeneous networks and hierarchical resource management.