04424421 is referenced by 20 patents and cites 10 patents.

A telephone subscriber testing system is disclosed in which all tests may be performed from a central office. A central office test device is connected to the central office by a separate telephone line with a telephone number of its own. Moreover, a dedicated command channel connects the office test device with a remote test device over the carrier lines. This dedicated channel is used to communicate commands and transmit test results back to the central office. By causing the remote device to "dial up" the office device, the entire trunk loop through the PCM trunk and the central office switching equipment can be tested directly in one measurement at the central office.

Title
Apparatus for testing subscriber carrier systems
Application Number
6/314212
Publication Number
4424421
Application Date
October 23, 1981
Publication Date
January 3, 1984
Inventor
Thomas Streenan
Carson City
NV, US
Todd V Townsend
Reno
NV, US
Agent
Weissenberger and Peterson
Assignee
Lynch Communication Systems
NV, US
IPC
H04M 3/32
H04M 3/30
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