DLM is really strange.

I switched ISP's and had no G.INP - think the line sync'd at 56Mbps - at 6db SNR.

About 7 days later I got G.INP - that pushed me up to around 65Mbps.

After about 6 weeks I noticed drops at 2am every 2/3 days. DLM would never go past 4db though. Then it put me up to 5db and left me there for 2 months.

I decided to get a new modem as the HG612 was old. Same thing. It pushed for 4db and ended up back on 5db.

I removed the front of the 5C and plugged it into the test socket about 6 months in and it's now settled at the sync speed in my sig at 3db on retx low. The D side is around 350m.

Does DLM not take FEC's into consideration?

Removed front of the 5C will make no difference in Test Socket to DLM. Also DLM will not bother about FEC Errors. (only the CRC, ES, SES Errors & if resync more than 5 times in the space of 24 hours)

Edited by adslmax (Fri 23-Oct-20 09:59:14)

In reply to a post by adslmax:

Removed front of the 5C will make no difference in Test Socket to DLM.

It can and does.

If internal wiring is connected poorly it can make a massive and immediate improvement.

Also DLM will not bother about FEC Errors.

I and others believe it does.

My FEC errors once get 87000 on downstream but no DLM act.

Edited by adslmax (Fri 23-Oct-20 12:05:34)

And my FEC has been at over 1 million per minute with no DLM action.
That doesn't mean DLM doesn't use it.

It's my opinion that DLM doesn't punish a line for high FEC but it takes FEC in to consideration when deciding whether to remove actions.

For example DLM won't remove interleaving or Retx High if the FEC numbers are too high.

That's the DLM strange way! No ones know when it will bite the line change in fast path, interleaved, low retx, high retx, snr 3dB or even banded.

low retx end up IP Profile 96.69% from sync rate and high retx end up IP Profile 91% from sync rate

Edited by adslmax (Fri 23-Oct-20 12:16:43)

That IP Profile only applies on BT Wholesale circuits. AIUI the OP is on TT backhaul.

You seem to be posting useless information a lot these days Max. Even when it is correct it is rarely relevant to the discussion at the time.

Thought BTw and TTB are same IP Profile because it still controlled by Openreach for all FTTC lines, if not, explain what the difference?

In reply to a post by RobertoS:

That IP Profile only applies on BT Wholesale circuits. AIUI the OP is on TT backhaul.

You seem to be posting useless information a lot these days Max. Even when it is correct it is rarely relevant to the discussion at the time.

While only BT Wholesale have a publicly viewable IP profile system, all backhaul providers have to apply their own limit to downstream traffic based on sync speed.

With Talktalk and Sky backhaul this gives identical throughput values as BTw with around 96.7% on Retx Low and between 91-92% on Retx High.

5C's can and do fail.

I don't know if mine was faulty but the random noise bursts and ES's disappeared when I removed it.