Everything Ive seen says Code Violations, which totally rules out FECs. Code Violations could be either CRCs/ES/SES. Im pretty certain it doesnt use CRCs, it would be far to easy to exceed the MTBE, plus Ive exceeded that a few times myself over the past week or so and touch wood the DLM left me alone.
The Element Manager only has one parameter for errors which it uploads to the Management Device for DLM. As far as DLM goes all the Management Device (RAMBo) seems to need from the Element Manager is uptime, Errors, retrains & sync speed.
There is another file that the Element Manager produces, but thats just a very simple binary file, which RAMBo uses to identify wide area events and unforced retrains.
Oh and the OSS keeps a record of line data for a period of time, but I think thats more to do with say when the ISP says runs a WHOOSH and for fault finding, and nothing to do with DLM/RAMBo.
The only thing up until last week that said anything specific was a mention of ErrSecs and SES.. then Zen came up with the FECs.
However last week BS checked and found this:
From a DLM doc ...... backing up Kitz comments.
Mean Time Between Errors (MTBE) = Uptime / Errored Second Count. MTBE measures errored seconds only (Not HEC, CRC or FEC).
There is one instance though when DLM will perform additional monitoring and thats when a line goes Scarlet (Very Poor). At this point RAMBo goes into overdrive and kicks the
Element Manager into touch, bypassing it completely. It then undertakes intensive monitoring of the line direct with the DSLAM. During
additional line monitoring, RAMBo looks at other parameters such as SNRm to see if it can figure out whats going on. During this intensive care stage, a line's DLM can be immediately changed, it doesnt have to wait for the normal 24hr monitoring reports. Im beginning to wonder if this is where FECs may have crept in
RAMBo does not directly monitor every single line, the vast majority of lines data gets collected by the DSLAMs Data Collectors and over to the Element Managers... then once a day to RAMBo.
Im still open to the possibility of FECs being used, but atm Ive seen nothing in writing which would back this up. Its the blip logic/doubler process which is used to decide when parameters are removed. It may also depend on which parameter caused the DLM to kick in because these are permanently recorded as RED(retrains) or CRIMSON(errors)
---
PS Im saying RAMBo only because most people are familiar with that name, but strictly speaking it should now be called Management Device. The DLM has now become
the major function and the RAP process does comparatively very little since 21CN/FTTC - and absolutely nothing for the GEA Fibre lines.