I strongly suspect its the number of LOFs which is upsetting the DLM, not the Err Secs.. which may also explain why its increasing the TNM rather than INP.
This is the reply I started the other night but didn't finish. I'm mega busy for the next few days and then I go AWOL for a while so I may as well post it now.
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It's looking like the LOFs can cause DLM action. But we have to be a bit careful if deciding whether an LOF could count towards DLM as you'd need to take note of the last retrain reason
According to your stats "Retrain Reason: 1" which we generally take to indicate that the resync was caused by DLM - see here here RDI detector code
linky.
This sparks a few other questions, the main ones being
Is DLM using RDI codes for calculation of MBTR or ignoring any RDIs?
Do Line tests cause an RDI?
We may also have to be careful when distinguishing between retrain reason = 1 being an RDI and the RDI indicator mentioned in the ITU specification
RDI's only occur when an LOF is initiated at the DSLAM without a SEF defect.
LOF between the modem and DSLAM direction are highly likely to be counted towards MBTR.
Linestats show SFErrors but don't record what could be SEFs so we may not always know which downstream LOFs are being counted by DLM
From ITU G.992.1
D.2.1 LOF-rs: Loss of ADSL frame synch/resync event. This event occurs when some algorithm,
which may be vendor-specific, determines that a resync attempt is required. Note that this LOF-rs
event is probably (but not required to be) related to the SEF (severely errored frame) defect defined
for operations and maintenance (see 9.3).
So now lets look up the relevant sections relating to SEFs which trigger a LOF
9.3.1.3 ADSL line related near-end defects [path from the modem to DSLAM]
Severely errored frame (SEF) defect: An SEF defect occurs when the content of two
consecutively received ADSL synchronization symbols does not correlate with the expected
content over a subset of the tones. An SEF defect terminates when the content of two
consecutively received ADSL synchronization symbols correlate with the expected contents
over the same subset. The correlation method, the selected subset of tones, and the threshold
for declaring these defect conditions are implementation discretionary.
9.3.1.4 ADSL line related far-end defects [path from DSLAM to modem]
Far-end Remote defect indication (RDI): An RDI defect is an SEF defect detected at the
far-end and is reported once per superframe by the RDI indicator. The RDI indicator
(see 7.4.1.1) shall be coded "1" to indicate that no SEF defect is present in the previous
superframe and shall be coded "0" to indicate that an SEF defect is present in the previous
superframe. An RDI defect occurs when a received RDI indicator is set to "0". An RDI
defect terminates when a received RDI indicator is set to "1".