Addressing the developments in optical networking, this guide covers the market for advanced optical communications products used by interexchange carriers (IXC)/internet service providers (ISP), incumbent local-exchange carriers (ILEC), competitive local-exchange carriers (CLEC), and cable-television (CATV) operators. The focus of this research report is on next-generation systems that include the new generation of synchronous optical network (SONET) systems, which offer more intelligence and lower cost than previous generations of such systems, and commercial products that have begun to embody the dream of an all-optical network. Both transmission and switching equipment are covered.