Multi-class applications for parallel usage of a guaranteed rate and a scavenger service

Grid computing requires network services beyond what is currently provided by the Best-Effort Internet. Among the different approaches towards network Quality of Service, aggregate scheduling, which maps micro-flows to a small number of different service classes, offers sufficient scalability up to the size of the Internet. The Differentiated Services architecture of the Internet Engineering Task Force is such an approach. Recently further Best-Effort like services have been proposed that are based on aggregate scheduling, like the less than Best-Effort Scavenger Service and the Alternative Best-Effort Service. In this paper we introduce the existing aggregate based approaches to Quality of Service. We take a heterogeneous mix of Transmission Control Protocol and User Datagram Protocol flows into account and complement services by adding transport protocol specific elements, if appropriate. In particular we show multi-class applications that are designed to apply a Guaranteed Rate Service and a Scavenger Service in parallel. Doing so we can show a performance gain and achieve a more economical use of the available resources without impacting responsive Best-Effort flows.