 (OAM&P) capabilities. Such capabilities reduce the operations cost, which nearly always exceeds the amortized equipment cost, particularly for large- deployment environments. Some of the simplistic management tools avail- able on campus-derived architectures (for example, virtual LAN [VLAN] architectures) become significantly problematic from a productivity stand- point when the base of network elements reaches into the hundreds range. Both the topological and the OAM&P capabilities of SONET are needed by service providers to support large-scale networks. Users and providers consider Ethernet to be a well-known, well- understood technology with a high comfort level among technical experts and network operators. Before deciding whether to use Ethernet-backbone- based networks or next-generation SONET-based networks to deliver new broadband services, service providers should first understand the issues and opportunities surrounding end-to-end Ethernet networks and/or transparent LAN service (TLS), ²2 and then begin to incorporate Ethernet- based paradigms into their service development and deployment plans. Only then can they ascertain the extent of the impact on the proposed net- work architecture. And more than ever, carriers need to be mindful of their network design actions in regards to profitability. A general data network infrastructure usually has three different levels: 1. Access networks include the local access facilities between a service- providing node (SN), central office (CO), or POP and the customer premises network. The customer premises network is comprised of a building, riser, and campus elements. Ethernet is the dominant technology for the LAN at both the floor and backbone levels. The access link is the last/first mile between the metro core/WAN network and the customer premises. Today, the provider usually owns the access network. The access link is mostly based on narrowband copper transmission technologies. The speed of the access link is therefore lower than Ethernet, Fast Ethernet, GbE,