电信专业英英词典L-2（在线收听）

　　Loop Length

　　Typically, loop length is a complete electrical circuit; the pair of wires that winds its way from the central office to the telephone set or system at the customer's premises.

　　Loop Signaling

　　Loop signaling is a method of signaling over dc circuit paths that utilizes the metallic loop formed by the line or trunk conductors and terminating circuits.

　　Loop Start

　　Loop start is a supervisory signal given at a telephone or PBX in response to closing the loop's DC current path.

　　Loop Transmission Facilities

　　Loop transmission facilities connect switching systems to customer premises equipment throughout the serving area. A loop is a transmission path between a customer's premises and a LEC central office. The most common form of loop, a pair of wires, is also called a line. A loop" can be derived from digital loop carrier (DLC) systems also referred to as subscriber loop carrier (SLC) systems.

　　LSI

　　large-scale integrated circuit

　　LAN - Local Area Network. A data communications network that lies within a limited space (such as a building) to connect telephone lines, computers, modems, printers, etc.

　　Local Access and Transport Area (LATA) - Geographical boundaries within which local telephone companies may provide local telephone services (and some limited toll services). There are 184 LATAs in the United States.

　　Leased Line - A phone line dedicated for exclusive use from one location to another. High speed connections require a leased line.

　　Lifeline/Link-Up Program - A Federal program designed to provide telephone service to the poor and elderly at a reduced cost to assure they can be reached in case of an emergency.

　　Link - See Hypertext Link

　　LISTSERV - Mailing lists that act as newsgroups.

　　Local Number Portability Charge (LNP) - Allows a customer to keep the same phone number and "port" it over to another service provider. This is new to wireless. The terms number portability (NP) and local number portability (LNP) are often used interchangeably.

　　Local Number Portability Charge (LNP) - This charge may appear on the local portion of a phone bill if you live in an area where local number portability is provided. This fixed monthly charge allows local telephone companies to recover certain costs for providing “portability” to its customers. Local telephone companies may continue to assess this charge on their customers’ telephone bills for five years from the date the local telephone company first began itemizing the charge on the bill. This is not a tax.

　　Login Name - The unique account name used to access a computer system. Also called user ID or user name, it is a way people identify themselves to their online service or Internet access provider.