Viop phone - Voice Over IP

The Local Loop

Prior to 1984, AT&T owned most of the network through its local Bell operating telephone companies. A layered hierarchy of office connections was designed around a five−level architecture. Each of these layers was designed around the concept of call completion. The offices were connected together with wires of various types called trunks. These trunks can be twisted pairs of wire, coaxial cables (like the CATV wire), radio (such as microwave), or fiber optics. As the convergence of voice and data networks continues, we see a revisitation to the older technologies as well as the new ones. Fiber is still the preferred medium from a carrier’s perspective. However, microwave radio is making a comeback in our telecommunications systems, linking door−to−door private−line services. Carrying voice, data, video, and high−speed Internet access is a given for a microwave system. Light−based systems, however, are limited in their use by telephone companies. It has been user demand that has brought infrared light and now Synchronous Optical Network−based (SONET) infrared systems in place. Recently, the introduction of an unguided light introduced by Lucent Technologies operates at speeds up to 2.4 Gbps to 10 Gbps. This offers the connectivity to almost anyone who can afford the system, because the right of way is no longer an issue.