Service providers are now offering Ethernet services over their metro and nationwide telecom networks. The established providers (e.g., ILECs) have adopted the Ethernet-over-SONET (EoS) architecture, which leverages their legacy SONET footprint, as the foundation to carry these services. More importantly, it allows for the creation of novel data services that marry the reliability of SONET transport with the flexibility required for data traffic. In this talk, we explore the opportunities and management requirements in deploying such services. Given Ethernet’s “best-effort” underpinning, the key challenge for providers is to offer some level of “carrier-grade” reliability. To that end, we highlight issues in delivering guaranteed-bandwidth Ethernet line (or, E-line) and Ethernet LAN (or, E-LAN) services. In particular, we focus on the specific problems of E-Line protection routing and the bandwidth-aware spanning tree design for E-LANs. We abstract the theoretical formulations, provide algorithmic solutions and present performance results. We argue that leveraging emerging protocols such as Virtual Concatenation and LCAS is key to effective solutions in practice.