Managing and pricing service level agreements for differentiated services

We present an approach to managing and pricing service level agreements (SLA) for differentiated services that uses a simple upper bound for the effective bandwidth of the conforming traffic as a proxy for resource usage. The bound depends on the user´s traffic profile (peak rate and token bucket descriptor). Usage charges for a specific time period are proportional to this proxy, and their calculation requires only measurements of volume. We discuss and present experimental results regarding the incentives and fairness of the proxy, which is required in order to achieve economic efficiency. An important feature of our approach is the simplicity of the user´s procedure for selecting optimal token bucket parameters. Our approach is quite generic and can be applied to scheduling disciplines that enable the provision of multiple service classes with different levels of performance. Finally, we present a case study for two service classes, real-time and non-real-time, with actual Internet traces