Carrier-grade Ethernet is the latest step in the three-decade development of Ethernet. This work describes the evolution of Ethernet technology from LAN toward a carrier-grade operation through an overview of recent enhancements. After reviewing native Ethernet and its transport shortcomings, we introduce the major carrier-grade upgrades. We first discuss the evolution of layer-2 architectures. Then, we detail the service specifications and their QoS and traffic engineering requirements. Finally, we describe the new OAM and resilience mechanisms.
