hich defines ATM virtual path support on SONET rings; and GR-2842, which denotes the requirements for ATM-based access multiplexers. A second approach to obtaining an increased level of efficiency is indi- cated by the second protocol stack shown in Figure 6.16. In this example IP frames are transported over SONET/SDH networks. Currently there are no standards governing the transport of IP frames over SONET/SDH. However, IP could be used within traditional T- and E-carrier facilities to be carried in fixed positions within a SONET or SDH frame. The third approach shown in Figure 6.16 is to adapt all services to IP frames for direct transport over an optical network, bypassing the use Figure 6.16 ATM Transport Packet over IP over fiber Alternate emerging Services SONET/SDH Services Services optical transport facilities. SONET/SDH SONET/SDH Optical Optical Optical Fiber in the WAN of SONET/SDH. Although there are no standards for this approach, some relatively newly formed communications carriers have implement- ed this approach using DWDM to obtain multiple IP transports at the OC-48 and OC-192 rates, thus providing a tremendous bandwidth capaci- ty as well as the efficiencies of IP frames being transmitted only when there are data to transmit. Of the three approaches, it is the educated guess of this author that IP over fiber will evolve as the method of choice for many carriers. This page intentionally left blank. CHAPTER Fiber in the Neighborhood Chapter Seven The objective of this chapter is to provide readers with information concerning two potential large and evolving markets for fiber-optic components. One market, usually referred to as fiber to the curb (FTTC), represents the extension of fiber-optic technology to a central location within a residential or business area. From the curb, transmission occurs via conventional copper cable into the home or office. The second market for the use of fiber-optic components that we will examine in this chap- ter is fiber to the home (FTTH), which can also be conside