IEEE Ethernet passive optical networks support the SIEPON-defined data link protection for mission-critical services in a flexible, cost-effective, and reliable manner, addressing the need for guaranteed link availability for mobile backhaul applications, business customers, institutions, data centers, campuses, and so on, serving hundreds or even thousands of subscribers. In this article, we look at the motivation behind the EPON protection schemes from a network operator perspective, as well as ways of delivering increased data service availability while minimizing the impact on the network cost and complexity. We also examine mechanisms used in EPON for link fault detection, spanning from physical through logical to link layers.
