A Made IT project


Local Loop

The Local Loop is the line from the customer premisis to the local telco office. This line connects you to the nearest facility of the local PTT. The cable used is generally 26 AWG unshielded twisted pair cable (but it can be fiber also), with runs of about 2.5 miles or 4 km length. Most lines do carry only a single call, but more calles are possible (ISDN, xDSL). The Local Loop is terminated at two points. One is the connection at the customer premisis and the other is the connection to the channel bank or mux at the local telco office.

There are two types of connections:

Analog lines
Analog lines are always copper. The lines could be used for voice and data and can be dial-up or leased lines. The specificness about these lines is that the information is transported through the wires in an analog way, meaning sine waves are used and not ones and zeros, like in digital lines. The terminals on these lines are often telephone sets or modems. For a description of these devices see their corresponding pages.

Loading Coils
To assure electrical consistency over the entire analog copper line loading coils are placed in the line. Loading coils can not be used in digital links, because they absorb digital pulses.

Digital lines
Digital lines may be copper or fiber.