Definition of LOCAL LOOP in Network Encyclopedia.
What is Local Loop?
Local Loop is the portion of the telephone system that connects your home or office to the nearest central office (CO) of your local telco.
The wiring used in the local loop is usually unshielded twisted-pair (UTP) cabling, the transmission method is analog transmission, and the maximum distance from the telco’s CO to the subscriber’s customer premises is about 5 kilometers.

NOTE
In many urban and commercial areas, the local loop is being upgraded to Integrated Services Digital Network (ISDN), which uses the same wiring but provides all-digital communication for better voice and data connections. Asymmetric Digital Subscriber Line (ADSL) is another technology that is becoming popular, especially for high-speed residential Internet access.