This object sets the receive gain applied on the ATI port, chosen from a scale of enumerated values spanning -20.0dB to +1.5dB in 0.5dB steps, defaulting to rg42 (0.5dB). Admins adjust it to compensate for signal loss or excess level on the incoming analog path so voice quality matches the far end. For example, an admin dealing with a weak incoming signal over a long analog trunk might raise this from the default toward a higher gain value like rg44 (+1.5dB).