There is no period, it's a falacy that ISPs tell you so that you have difficulty declaring a fault with the service within the first x days.

DLM is on from the time the service goes live, it doesn't turn off.

In reply to a post by mrkevlh:

In reply to a post by WilliamGrimsley:

Finish what? This 14 day period doesn't exist on VDSL.

How long is it then, 10days? There certainly is a period of time whilst DLM adjusts your line during an initial connection.

Day 1: I got about 68Mbps (originally this was 79Mbps. Latency increased to 22ms.
Day 2: SNR increased from 6.3 to 7.3 and speed bumped back up to 79Mbps.
Day 3: SNR decreased back down to 6.1. G.INP was turned on.
Day 4: Latency dropped to 13ms.

DLM will take 2 weeks straight, or 14 days to complete, no less and no more. After that it just constantly monitors your line but does nothing pretty much unless you have a fault, or turn your modem on and off enough to mimick a fault.
Some ISP�s policies is to allow the DLM to expire those 14 days before continuing to report a fault if you still have one.

Edited by markyr74 (Sat 15-Dec-18 16:01:47)

That applied to BT Wholesale ADSL, and the period was 10 days - and this was largely to set the FTR/MSR so if DLM later altered the line and the rates were lower than originally "trained" within that 10 days, it was considered a fault.

It does not apply in the same way with VDSL on Openreach hardware, regardless of the ISP.

Matt

Edited by uno (Sat 15-Dec-18 16:50:18)

Both of you are correct in some ways, and both incorrect in others.

For a start, DLM on ADSL2+ and DLM on FTTC act in completely different ways. The first acts on BT Wholesale MSANs/DSLAMs at the exchange to BT Wholesale specifications. The second works on Openreach DSLAMs in the cabinets, to Openreach specifications.

The only significant commonality between them from the end user point of view is that for BT Wholesale-based ISPs an IP Profile is applied by the BT Wholesale BRAS system for both ADSLx and FTTC when it is notified of the connection speed and applied in their backhaul.

It is not applied (so far as I know) in the Openreach DSLAMs. It is nothing to do with Openreach.

The 10-day period, as WG says, is a complete myth. On both services. On ADSLx it is used purely to calculate the Maximum Stable Rate and Fault Threshold Rate, which are set by the lowest sync during the 10 days. The actions the DLM takes during that ten days are just like they are all the time.

FTTC DLM has an initial "grace period" of 24-48 hours when DLM basically works and may take a few hours to settle from first connection, but in seriously unstable lines will cap the maximum sync in both directions to obtain stability. It can also cap the line at any future time if certain criteria are exceeded.

I don't think there has ever been a 14-day period involved for anything technical. The nearest I can think of off-hand is the ten working days Ofcom stipulate for a migrating user to change their mind. Even that isn't always 14 calendar days, as Bank Holidays are excluded as well. Not just Saturday and Sunday.

Snap. I'm more verbose, but less authoritive .

And re the Subject Matt, as I think I've said in the thread, (maybe not), uno means one! Which is no doubt the reason for your choosing it.

I went for short and sweet!

Kitz has a good write up on DLM - https://kitz.co.uk/adsl/DLM_system.htm

Training & Stabilisation - Setting the MSR and FTR. The stabilisation period is a 'one off' event that occurs during the first 10 day training period with adsl connections. Details about the MSR and FTR are explained elsewhere on the site: MSR & FTR.
FTTC does not have a training period. The FTR is set at 15Mbps for lines which sync at >15Mbps or 2Mbps for lines which sync between 2-15Mbps.

Matt

In reply to a post by uno:

It does not apply in the same way with VDSL on Openreach hardware, regardless of the ISP.

Though the BT Wholesale checker erroneously says it does . Amongst other faults on its display such is "premise" in some recent additions rather then the correct "premises" already (and still present) there in earlier editions.

It is slowly spreading through Group publications.

Maybe identically would have been a better word...

Matt

Edited by uno (Sat 15-Dec-18 17:06:06)

It does run for 2 weeks, it did it twice this year on my line due to my messing about with equipment, speeds are capped and are put back after two weeks. And that�s a fact. No idea where you got your info from.

In reply to a post by uno:

Kitz has a good write up on DLM - https://kitz.co.uk/adsl/DLM_system.htm

So have I . More noddy level as intended, and needing updates. But correct in principle.

I do have a more technical question though. I'll get back to you later on that.

BT Wholesale As at 2013.

Openreach As at 2013.

10-day training period As at 2010.

Edited by RobertoS (Sat 15-Dec-18 17:15:27)