Interleaved Polling Algorithm with Service Level Agreement (SLA) to Improve QoS in Ethernet PONs

We propose a dynamic bandwidth allocation algorithm for ethernet passive optical networks (EPON) called IP-SLA (interleaved polling with SLA) to offer quality of service (QoS) in the upstream direction. IP-SLA differs clients inside the network as it takes into consideration the service level agreement (SLA) contracted by each subscriber, achieving better performance for the highest service levels agreement in terms of both mean packet delay and packet loss rate. On the other hand, IP-SLA also provides service differentiation based on the strict priority queueing method, which provides the minimum mean packet delay for the most priority services without considering the penalization caused to the lowest priority traffic. However, our algorithm keeps the mean packet delay for the most priority classes of services inside the specified bounds and uses the remaining resources to improve the performance of the lowest priority services in terms of mean packet delay and packet loss rate.