Service level agreements: A main challenge for next generation networks

Service Level Agreement (SLA) specification and management becomes a key differentiator in the service provider's offerings. SLA management will allow service providers to offer different levels of service guarantees and to differentiate himself from its competitors. It will improve its ability to satisfy customer expectations, as the customer will exactly know what to expect in terms of quality of service. SLAs are also a key requirement for the deployment of multimedia over the Internet, i.e. for Next Generation Networks. The Internet today is however a best-effort network, without the need for such strict contractual guarantees. Therefore numerous initiatives are currently undertaken to specify SLAs and to identify the new challenges for the provider's service and network management. The aim of this paper is to present a high-level overview of the main SLA-related issues: the actors involved in SLA negotiations, the technical specification of SLAs and the mapping of SLAs to service classes. We give an overview of ongoing SLA-related initiatives in the industrial world, standardisation bodies and the research community.