A Study of Marking Aggregated TCP and UDP Flows Using Generalized Marking Scheme

Abstract

End-to-end Assured Service may be provided by the combination of assured service models over multiple domains through service level agreements (SLA) between two neighbor domains. Many studies revealed that the current assured service model does not meet the target rate of large-profile TCP flows in the presence of numerous small-profile TCP flows and that it does not equably distribute the profile rate of an SLA with multiple flows that are included in the SLA. We proposed a marking rule, called G-Marking (Generalized Marking) in order to diminish these problems simultaneously. The G-Marking consists of an Ingress marking scheme (I-Marker) and an Egress marking scheme (E-Marker) that are performed in ingress and egress routers respectively. In addition, there is another unfairness among UDP flows and TCP flows. In Internet, USP flows and TCP flows are mixed but TCP flows are seriously affected by USP flows. Thus, the G-Marking should effectively support this Internet traffic distribution and so this point is focused in this paper. Two experiments with the ns-2 simulator were performed: with E-Marker and I-Marker respectively. Simulation results show that compared to other schemes, G-Marking can more greatly correct the current problems.