On the monitoring of contractual service level agreements

The goal of monitoring contractual Service Level Agreements (SLAs) is to measure the performance of a service, to evaluate whether its provider complies with the level of Quality of the Service (QoS) that the consumer expects. The aim of this paper is to bring to the system designer's attention the fundamental issues that monitoring of contractual SLAs involves: SLA specification, separation of the computation and communication infrastructure of the provider, service points of presence, metric collection approaches, measurement service and evaluation and violation detection service. The paper develops an architecture and give reasons why currently it is practicable to offer guaranteed QoS only to consumers sharing Internet Service Providers (ISPs) directly with the service provider.