us has been on developing an array of new Layer 2 protocols of all kinds rather than on lowering the per-building fiber access cost, which is comprised of the spur cost and the in-building equipment cost. However, there are also endogenous issues. Local services (such as a cab ride at $1.50 per mile) are intrinsically more expensive than long-haul services (such as air transportation, which is generally $0.25 per mile) because of the much smaller base upon which facility costs can be dispersed (for example, an access fiber can be shared among a handful of users-say, one to four users-whereas a long-haul fiber can be shared among several thousand users) and because of the economy of scale of the equipment that has to be used. Finally, there are regulatory and open-competition reasons. Industry efforts need to focus on bringing innovative technology to the metro edge of the public service network, which as noted where nearly all the bandwidth scarcity and connectivity bottlenecks currently are. These optical systems need to deliver an optimized blend of user-preferred Ether- net access protocols, broadband speeds, cost-effective fiber-optic pair gain, multimedia support, and distance bridging via a family of price-perfor- mance-specific field-upgradeable platforms, enabling next-generation car- riers, incumbents, and ISPs to efficiently deploy end-to-end Ethernet services (as well as traditional private-line services) faster, farther, and more flexibly than possible at the present time. However, although new Ethernet-based technologies are being applied to the MAN environment, Chapter 1 traditional architectures and technologies, specifically SONET/SDH," are making major strides in improving their price-performance points, sus- taining the assault from the new alternatives, and cementing themselves as formidable embedded solutions. The SONET/SDH transmission protocol is used by carriers seeking to provide carrier-class services because it provides the needed Operations, Administration, Maintenance, and Provisioning