FTTC DLM query

[Andrew600]

I just realised something I should have checked all the way back at the start of this, but didn’t think to check because the landline had just been repaired.
The phone is humming on a quiet line test. It’s not noisy enough to interfere with calls, but it’s not silent either.

It’s an old phone temporarily plugged into the master socket, not a dect by the way.

Fault reported….again.

I’m guessing it could well be why DLM hasn’t done anything to increase speeds.

[licquorice]

Indeed it could well be.

Possibly an earth contact fault causing the hum.

[Andrew600]

No nearer a solution after the latest Openreach visit sadly. 
The fault has apparently been detected as being 100+ metres beyond our street cabinet and is not easily repairable because of a collapsed/damaged duct.

A request for complete replacement of the offending cable has been made today, but I dread to think of the timescale involved with that. Potentially a road closure would be needed. The OR engineer certainly wasn’t prepared to make a guess.

A question please and me thinking out loud really. 

Given the cable from the cabinet to us is said to be perfect, is there anyway I can force a switch to digital voice despite it being copper from the cabinet? That would bypass the problem by cutting power to the offending cable wouldn’t it?

Failing that, should it drag on, I guess I could try to renegotiate a broadband only connection to achieve the same thing and switch the household to 100% mobile.

[licquorice]

The fault can't be on the 'E' side (beyond ) of the cabinet as that isn't carrying the broadband and thus DLM.

Scrap that. Yes, it could affect the 'D' side as well as there is a DC path through the cabinet.

If you moved to DV, there would no longer be a DC path through to the faulty E side, so yes, it should clear your fault.

[Andrew600]

Thanks @licquorice

I’m pleased my thinking wasn’t totally wrong.

I think what I’ll do is live with it over Christmas to see if any repair eta appears, but as BT have just sent me the standard your service should be fixed now message I suspect I might not have any idea what’s happening going forward. I suppose I’ll have to mark it as not fixed and see.

If nothing acceptable is proposed, I can then discuss the options with BT retail from a stronger position.

As an aside, the engineer implied quite strongly that they are fed up with dealing with the neglected copper network. I can sympathise. I’ll be glad to see the back of it too. Sadly FTTP is only estimated for by Dec 2026 for us.

[Andrew600]

It looks like BT are now aware that it’s an ongoing fault, so that’s a small positive.

I just received this.

”We're sorry, but we need to do some more work to fix your fault. This means it'll be a bit longer before we can get your service up and running again.
We'll let you know as soon as we have more news for you.”

I’ll park this one for now and reassess in January.

[Andrew600]

A small unexpected update.

24 hours after the email posted above, BT unilaterally marked the fault as fixed despite me saying it wasn’t.
Whether Openreach have any plans to fix it properly I have no idea. I’ve lost all means of tracking progress.

I still plan to wait until January before doing anything else.

[Andrew600]

Another update, positive this time.

The E side copper fault has definitely not been fixed, but DLM appears to have reduced the noise margin to 3 over night.

Although the maximum data rate is much lower than it used to be and seems to be reflecting the effects of the fault, I’m now getting all of that data rate delivered to the hub, so essentially I’m back to normal….for now anyway.
Fingers crossed that it stays like this.

Hub log looks like this at the moment.

DSL uptime:0 days,06 Hours59 Mins57 Secs

Data rate:19.999 Mbps / 79.999 Mbps

Maximum data rate:30.755 Mbps / 74.423 Mbps

Full Fibre (FTTP) Mode:Off

Noise margin:11.5 / 3.1

Line attenuation:5.1 / 9.1

Signal attenuation:5.1 / 10.5