 also considered CLECs. For simplicity's sake, the common denominator among CLECs is that their offerings are centered primarily on voice services. Internet Service Provider (ISP). ISP is also a broad term and can refer to any company that offers Internet access services, whether by dial-up or more robust dedicated lines, such as DSL connections. Internet service providers also tend to offer value-added services such as e-mail, Website hosting, and information portals. Data Local Exchange Carriers (DLECs). A DLEC is a company that primarily offers data services to business customers. Such companies will provide Internet access capacity, up to about 1 gigabit, generally using leased circuits or optical capacity from other providers to access the customer premises. They will also link corporate locations using any combination of network technologies from VPNs to switched data services, such as ATM, frame relay or IP over private networks. It is these latter, more sophisticated The Ultimate Guide to Building and Delivering OSS/BSS services that differentiate a DLEC from a more traditional Internet Service Provider (ISP) that provides only Internet access and basic related services. Building Local Exchange Carriers (BLECs). What makes a BLEC is based more on strategy than technology. A BLEC will tend to offer a full range of services, including voice, data and even video. Its strategy is often to rewire a commercial, multi-tenant building for high capacity voice and data services and locate network equipment on premises. The building is then linked to a LEC central office through a high capacity line, such as a T-3 circuit. The BLEC will then target the businesses within that building as their full service provider, offering them high-speed data, multi-line voice services, Internet access, and geographically and demographically focused Web portals. Wireless Local Loop (WLL) or Fixed Wireless Providers. Often BLECs themselves, WLL providers base their strategies on fixed wireless technologies. Like any other BLEC, the