Conformance Study for Networks with Service Level Agreements

To achieve some level of Quality of Service (QoS) assurance, a network usually has Service Level Agreements (SLAs) with its users and neighboring domains, which describe the QoS level the service provider is committed to provide and the amount of traffic users or neighboring domains are allowed to send. An interesting and important question arises as to whether a flow is still conformant to its original traffic specification after crossing the network since it may interact with other flows within the network. In this paper, we study analytically the extent to which a flow becomes non-conformant. In particular, we study such conformance deterioration through analysis of the burstiness increase of the flow after crossing the network. We analyze the stochastic burstiness increase of the flow after crossing certain network elements that include not only deterministic servers but also stochastic servers. We extend the analysis to end-to-end cases and aggregation cases. In addition, we establish the relationship between stochastic burstiness increase and conformance deterioration probability. Based on the relationship, we obtain a bound on conformance deterioration probability. Lastly we verify our theoretical results with simulation.