SNR Margin is the maximum increase in dB of the noise power received at the ATU (ATU-R on downstream direction and ATU-C on upstream direction), such that the BER requirements are met for all bearer channels received at the ATU. It ranges from -640 to 630 units of 0.1 dB (physical values are -64 to 63 dB). A special value of 0x7FFFFFFF (2147483647) indicates the SNR Margin is out of range to be represented. A special value of 0x7FFFFFFE (2147483646) indicates the SNR Margin measurement is currently unavailable. This object reflects the value of the parameter following the most recent DELT performed on the associated line. Once the DELT process is over, the parameter no longer changes until the row is deleted or a new DELT process is initiated.