Kitz Forum

Broadband Related => FTTC and FTTP Issues => Topic started by: ktz392837 on April 11, 2015, 01:08:28 PM

Title: What causes DLM to intervene?
Post by: ktz392837 on April 11, 2015, 01:08:28 PM

Does anyone know what criteria is used for the DLM to intervene?

Is a dropping db value just normal crosstalk and operation so eventually due to the dropping db because more and more connections to cabinet your speed gets slower or is that the DLM intervening?

Is a burst of 200/hr ES for a few hours enough to affect db / speed? After these few hours ES returns to <30/hr but the damage is done db dropped to low values and synced at much slower speed when next reset or resync.

Thanks

Title: Re: What causes DLM to intervene?
Post by: Chrysalis on April 11, 2015, 03:59:44 PM

snrm db is a variable value, there is a target of 6db but that only applies at the time of the sync event, after that point the db value will move around dependent on noise on the line.  crosstalk is one such generation of noise.

I have never known for DLM to take action on a line simply for have a low snrm, however as snrm drops the error rate can increase which in turn can cause DLM action as DLM does act on the MTBE (ES count).

It may also act if there is too many loss of sync in a 24 hour period, in particular if these occur close to each other.