An End to End Price-Based QoS Control Component Using Reflective Java

The main objective of the model we describe in this paper is to allow easy, flexible addition of quality of service (QoS) control to Java Internet applications. In this work the QoS is expressed in terms of network and host resources, the network QoS being controlled with RSVP. Flexibility is provided by a prototype product from the ANSA research consortium; Reflective Java which uses the Meta Object Protocol (MOP) to separate functional requirements (what the application does) from non-functional requirements (how it does it). This protocol permits the design and implementation of a generic QoS control element which can be added to an application for which QoS control is required. Alternatively, an existing application with rudimentary QoS control can be modified to use a set of QoS control classes designed by a specialist intended to reconcile competition for QoS between applications. The QoS control element we have designed also has scope for QoS adaptation, moving decisions on the introduction of QoS control from build-time to run-time when best-effort degrades below a useful point. Charging is also considered in this work.