More on Telecommunications Wiring - Cabling

Most every home has local telecommunications wiring. It generally consists of one or two pairs of coated copper wire. One wire is called the tip, and carries no voltage. The other wire is called the ring, and carries -48 to -52 volts. These wires can be spliced together to provide multiple telephone jacks in any location for any given phone number. The telephone jack in your house is wired to the network interface box on the outside of the building. In some buildings, the network interface is located in the basement. It is where the local phone companys responsibility ends and the consumers begins, unless they have bought a service contract that includes inside wiring. This is the location that either the consumer or the telephone company uses to test the line. The network interface is connected to the pole via a drop line, where it joins hundreds, sometimes thousands, of other cable pairs. This cable leads to the telephone companys central office, where all local telecommunications wiring is terminated. Even if the call is destined to go across the street, it must first go through the central office. Cell phone towers are cabled to the central office. The cables leading to the central office may be underground or on poles. The central office contains computerized switching equipment that records billing information, then routes the call to the appropriate cable to achieve its final destination. The central offices are redundantly networked, meaning that each one is cabled to at least two others. They are also where cell phones, fiber, and DSL connect to fiber optic cables that go to the internet hub, allowing the consumer online access. Communication using a land line, cellular telephone, or internet is an important part of society today, and is all possible due to local telecommunications wiring.