topic Re: DSL dropping in Broadband

DSL dropping

WorStevo84NE — Thu, 26 Feb 2026 11:33:39 GMT

My Digital Subscriber Line connection is dropping repeatedly. The Digital Subscriber Line light goes out and reconnects several times per hour. It has happened six times in two hours.

There are only three realistic causes:

A minor fault somewhere on the external copper line (for example, a slightly damaged joint or moisture in a connection).
Electrical interference affecting the line.
The modem inside the Sky Hub becoming unstable when the noise margin is low.

The SNR is set to 3.9dB and I have FTTC so there must be noise on the copper wire.

What do I do?

Re: DSL dropping

Chrisee — Thu, 26 Feb 2026 14:57:32 GMT

@WorStevo84NE a noise margin of 3.9dB is near the minimum 3dB. If there is an increased level of noise the automatic. DLM system running in the cabinet will raise the noise margin in dteps each night until the line stabilises. Openreach do not intervene until the DLM system has failed to stabilise the line without dropping speeds below tge guarantee (likely noise msrgin around 10dB) or line drops exceed 10 per day. There is little Sky can do about this policy.

It is a fact of life with VDSL partial fibre lines that wet weather often causes lines to become unstable given the very wet weather it is a common issue. It is highly unlikely to be an issue with the Sky hub's modem stage as these are pretty reliable. Openreach are increasingly avoiding anything more than casual work on the copper network as they switch to full fibre which doesnt help those who have no other choice.

Re: DSL dropping

WorStevo84NE — Thu, 26 Feb 2026 21:25:03 GMT

Thanks for that. I will check everyday if the DLM has raised the dB margin. If not, I will contact Sky to send Openreach out.

Waiting in anticipation for the rollout of FTTP which should be here this year for my area.

Anyways, thanks again for the in depth explanation. ☺️