一种支持多用户SLA的EPON上行带宽分配算法设计

在接入网服务等级协定的基础上,分析了以IPACT和CyclicDBA为代表的EPON上行动态带宽分配算法,讨论了其对EPON上多用户SLA支持所存在的固有缺陷。提出了适合SLA应用的EPON控制帧结构:授权帧和请求帧。根据这两种控制帧,设计了一种新型的支持多用户SLA的EPON上行信道带宽分配算法,等级轮询固定周期算法。通过理论分析和计算机仿真测试表明该算法针对EPON不同类型的接入用户均达到了较理想的性能指标,高优先级业务良好的时延和时延抖动特性,各种业务队列的尺度平稳,同时HPFCT还解决了传统轮询算法中低负载时下行带宽浪费明显的问题。

Design of DBA algorithm in EPON upstream channel in support of SLA

Based on the SLA (service level agreement) in access network, the inherent deficiencies of two classical DBA algorithms: IPACT and Cyclic DBA in EPON to support multi-user types were analyzed. Two new Ethernet control frames: grant frame and request frame were introduced and a novel DBA algorithm supporting multi-user types SLA in EPON system: HPFCT (hierarchy polling with fixed cycle time) was proposed. The theoretical analysis and simulation results show that this algorithm meets the standard of various user types: satisfied delay and delay jitter performance of high priority services, and stable buffer size of all sorts of services. At the same time, HPFCT solves the downstream bandwidth waste problem of conventional algorithms.