The Ethernet passive optical network (EPON) is an emerging broadband access networking technology that offers flexible bandwidth with simplicity, reliability and cost effectiveness. The automated discovery of optical network units (ONU) and the coordination of the operation between ONU and the optical line termination (OLT) is the mandate of the multi-point control protocol (MPCP). The auto-discovery mechanism is for finding newly attached ONU as well as reconnecting active (or recovered) ONU in case of service interruptions. On the basis of the IEEE 802.3ah MPCP, this paper introduces a set of enhancements to the auto-discovery mechanism. With these improvements, the EPON MPCP is able to support carrier-grade telecommunications services by recovering quickly from failures with minimum service impact. Moreover, it leads to a scalable and efficient scheme for balancing system response and bandwidth efficiency.