August 1999
Intermediate to advanced
328 pages
8h 50m
English
Content preview from Voice Over IP
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ACCESS-LINE SIGNALING
Access-line signaling can be implemented in a number of ways. The most common scheme used in the public telephone network is known as loop-start signaling. It is employed in the Bell Operating Companies' (BOC's) Message Telecommunications Service (MTS) for residence and business lines, the public telephone service, data/facsimile service and private branch exchange (PBX) or automatic call distributor (ACD) service (see Figure A-8).
Loop-start signaling requires that the network connect the "tip" connector to the positive end and the "ring" connector to the negative end of the power supply for an on-hook (idle) state. Stated another way, battery is on ring and ground is on tip. The voltage supply is usually 48 volts (V), ...