This paper describes an experimental line quality monitoring (LQM) system, which has been in regular operation in several IBM locations. The LQM system uses a System/7 to gather information about the analog phenomena that occur on telephone data transmission lines. It gathers the information without taking the lines out of service. Described are the ways in which the information from the LQM system is used in daily operations; for example, in one case, use of the LQM system contributed to an increase in circuit availability from 82 percent to 99 percent over a one-month period.
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