MIT Department of Electrical Engineering & Computer Science

SERVICE LEVEL AGREEMENTS AND THEIR MANAGEMENT IN PACKET NETWORKS

Dr. Debasis Mitra
Mathematical Sciences Research Center, Bell Labs Lucent Technologies

Tuesday, November 30, 1999
4:00 PM (reception following)
Room 35-225
LIDS Colloquium

Abstract

We propose a template for QoS-centered Service Level Agreements (SLA) and a framework for their real time management in multiservice packet networks. The SLA considered are for QoS-assured delivery of aggregate bandwidth from ingress to egress nodes, where the elementary entities are flows or calls of various QoS classes. A SLA monitoring scheme is presented in which revenue is generated by the admission of flows into the network, and penalty incurred when flows are lost in periods when the service provider is not SLA-compliant. In our SLA management scheme the results of a prior design are used, in conjunction with measurements taken locally at ingress nodes, to classify the loading status of routes as either undersubscribed or oversubscribed. Our resource management is based on Virtual Partitioning and its supporting machanism of Bandwidth Protection, which aims to carry as much of the offered flows at any time as is compatible with the protection of future undersubscribed routes. The effectiveness of SLA management is measured by the robustness in performance in the presence of great diversity in actual traffic conditions. We have built a simulation testbed in software called D'ARTAGNAN, from which we report numerical results for a case study. The results show that the SLA management scheme is robust, fair and efficient over a broad range of traffic conditions. (This is joint work with Eric Bouillet and K.G.Ramakrishnan.)