tical signaling can coexist, so a power company can maintain a single, multipurpose infrastructure. Those who wish to compete in the lucrative local access market have three choices. They can buy from existing local loop services from the LEC at a discount and resell them at a profit; they can build their own up-to-date digital networks, or they can combine these two strategies. The third choice is a popular one. Most companies that are trying to grab a piece of the local access market (e.g., AT&T, Qwest/US West, or MCI WorldCom/Sprint) are pursuing the hybrid approach. Ramifications of the Telecommunication Act of 1996 (derisorily referred to as the Attorney Employment Act) transcend the scope of this text. Monthly, weekly, and daily publications are the best source for the most current information-many good sources are listed in the reference sections of this book. The Deregulation Act has blurred the distinction between carrier types. For instance, when MCI provides local Video Communications: The Whole Picture service, is it a LEC or an IXC (we use terms such as LEC and IXC broadly throughout this text even though references may not be precisely accurate)? The act has fostered competition and perhaps more innovation and development than AT&T introduced throughout its entire monopoly. However, it has also allowed market consolidation and, consequently, control by a few dominant players. Corporate LAN/WAN ISDN-BRI Cable Modem Carrier Network Figure 11-1. Carrier Access Options. Two broad categories of digital circuit-switched WAN access services exist: dedicated and switched. In the following section, we will address the differences between these two categories. DEDICATED ACCESS In the past, customers usually connected a video communication system to a long distance carrier's point-of-presence (POP) through a dedicated digital circuit (sometimes called a private line). A dedicated digital circuit is a permanent configuration that routes traffic exclusively across the network of the carrier to which one is conne