Abstract: This paper addresses a Service Level Specification (SLS)-based quantitative edge-to-edge QoS management mechanism in access network. By using Ethernet Passive Optical Network(EPON), it well settles the insufficiency of bandwidth in IP, it selects a service class for user service by the evaluation algorithm of optimal ratio, because the evaluation formula of optimal ratio is based on the user behavior in market and takes into accounts burden element, price element, and performance element, it not only can support quantitative QoS in DiffServ by inducing traffic orderly distributed along the service class, but also can provide well performance with less cost. Experimental results have perfectly verified its metrics.