I'am well aware that no one knows exactly what parameters DLM monitors with respect to G.Inp re-tx profile selection,
The G.INP 'equivalent' of Err Secs is LEFTRs
SEFTR = Severe Loss of error-free throughput
LEFTR = Loss of Error Free Throughput - Count of seconds with a defect
As regards to what causes the DLM to relent its all rather vague especially once the line is banded. All the documentation I saw indicated that it depends on your
ILQ status being green for a period of time. Observations with lines that had been Interleaved bore this out, bearing in mind that there is also some sort of doubler system in place meaning each subsequent incident requires a longer period of ILQ green. BTw documentation repeatedly indicates the parameters of interest are ErrSecs and SES and one doc specifically ruled out FEC count. BS can confirm this as there was an equivalent Openreach doc. For clarity, absolutely none of the documentation or info came from him and were obtained from other sources long before. He was just trying to see if anything had been updated.
However, since the ASSIA court case which specifically seemed to target the Openreach DLM some changes were made that seems to make it exceedingly hard to reverse line caps. Those few that have done so naturally have taken an exceedingly long period of stability. My own line now must have been capped for over a year. I do still see that daily dose of SHINE which lasts for <1sec and the rest of the time it is perfectly fine and should have been ILQ green for extremely long periods of time.
I've pondered if the SNRM may be of interest - as there is some sort of linear relationship between the [Target] SNRM and amount of cap in place. eg incr SNRM by 1.5dB, 3dB etc. When we artificially limit the line speed it results in an artificially high SNRM.
I started off with the intention of deliberately not artificially restricting my line as an experiment to see if the DLM did relent on its own. It didn't despite having had what must be months of ILQ green... then I just got too lazy and too ill to care. Despite being capped at 60Mbps the line still does most of what I use it for now. My upstream is still at 20Mbps, but due to my circumstance I don't do any large amounts of uploading these days, so even what was a much used benefit when I first got FTTC, doesnt get the workout like it used to.