Using edge-to-edge feedback control to make assured service more assured in DiffServ networks

Abstract

Markers, one of the building blocks of traffic conditioners play a major role for resource allocation in a DiffServ network. Recently, there has been a considerable research interest in designing intelligent markers, tailored for TCP traffic. The transient congestion levels in the network can affect the TCP throughput adversely and have great impact on the effectiveness of the marker. To address this issue, we propose an intelligent marker, which relies on an ECN-like feedback control mechanism between ingress and egress traffic conditioners. We present the control architecture and the marker algorithm, and illustrate the benefits of the proposed marker in a DiffServ network. The marker was implemented in the NS simulator and extensive simulations were done to study its effectiveness in the assurance of throughput, especially under the case that AS flows require different target rates, and co-exist with the unruly UDP flows. The ECN-like feedback mechanism that we use for the marker is also suitable in an MPLS domain for providing signaling to the ingress router of a congested label switched path (LSP) to mitigate congestion via dynamic traffic engineering techniques.