Sometimes known as ‘line side recording’, a trunk recording solution interfaces directly with the analogue, SIP or ISDN PSTN trunks before they reach the PBX system. Trunk side recording uses high impedance ‘passive tap’ technology to interface to the incoming trunks without terminating the line or impacting on the strength of the signal. In these kind of configurations the incoming trunks are fitted with ‘T – splitters’ or ‘RJ45 doublers’, small pieces of kit fitted to the lines that sends the E1/T1 signal directly into the recorder.

The diagrams below illustrate the basic configuration of a trunk recording solution. Note how the recorder interfaces directly with the incoming lines rather than the extensions.