Updating master socket for fibre

[#1]

I used to have a tangle of ancient cabling and extension sockets, but a year ago got a phone engineer to rip the lot out, and they wired the black cable from outside into the socket nearest the street, such that it's the only one in the house. My ADSL router now connects to a microfilter on this one. I get good speeds (the exchange is very close) and line attenuation figures, but not very good line noise ones. Since this isn't really a proper master socket, if I were to order Plusnet fibre, would the engineer replace the socket when they visit? And if not, would there be any gain in me getting someone in to replace it myself?

[#2]

There's no requirement for Openreach to visit your property. The connection(s) for fibre are completed elsewhere. PN's HubOne is a combined router/modem and is self install.

If I'm not mistaken, you should not replace the master socket yourself. That would mean interfering with the BT line entering the property which is not allowed.

[#3]

Have you tried BT Quiet Line Test?
If phone line is noisy, you need to get that sorted first.

[#4]

You are not officially allowed to touch the master socket. However when your wiring was tidied up one should have been fitted. Are you sure that you haven't got one? Can you remove two screws and/ or pull the front off to reveal the test socket? If so you can change the faceplate for a filtered version, just check that you buy the correct type. There are older master sockets but for many years now only two types have been used. Some faceplates are retained by two screws, later ones clip on. They are not interchangeable.

If you find that you do not have a proper master socket then they are available see https://www.amazon.co.uk/Openreach-Telephone-Master-Socket-Faceplate/dp/B07NX2KC8Y/ref=pd_day0_hl_23...

Having one is very useful for fault finding should you have a problem and they can improve broadband performance.

[#5]

I wouldn't need to do this - it's obviously the same old extension socket. I had it done because the cable used to come in through the door frame, then do a bizarre route doubling round two internal door frames, arriving at an ancient oval box in the hall I remember from the 60s (which I suspect once counted as the official end of the GPO's responsibility), then continuing through some newer kind of junction box before routing all over the house through both internal and external cables to various extension sockets.

I had to do this because I replaced the entire front door and its frame - the existing cable simply couldn't survive that.

What the engineer seems to have done, is cut the cable on the outside wall between the wall fixing and the door frame, installed a small white junction box there, and redirected black cable from it through the wall into an extension socket that was already there. So that it's the only remaining phone hardware in the house. Thought this may not be 'official', I rather suspect it's better than the Heath Robinson situation it replaced.

[#6]

I have tried a quiet test. It sounds pretty quiet to me, but last time I looked my router was reporting 3.3 upstream and 5.3 downstream noise margin, which I understand is poor (even though I'm getting 20mbps speeds anyway).

[#7]

The way DLM works is that it balances errors against SNR. The lower the SNR the faster the line. BT use 3dB as the target on good fibre lines, I'm not sure if that is the same on ADSL. So if your line is stable then 3dB SNR is fine and is not indicative of there being anything amiss.

[#8]

Thanks @Baldrick1 for confirming.

When I Googled, I found statements that lower than 10dB was poor, but evidently there's more to it, and I wasn't interpreting them properly.

[#9]

BT used 6db is the standard SNR.
If BT increase SNR this could mean that there is noise present on the line this should be investigated further.
BT increase the SNR to lower the router sync speeds this allows the router to connect to a stable sync speed.
Use a corded Phone only dial 17070 the BT quiet line test option 2 then listen for noise for about 1min 30 sec just make sure it is clear if noise is present report as a line fault only.
If the line is clear of noise replace the filter and the cable from filter to the router this check if any of these where at fault.
If no noise present the problems could caused by the router been switched off regularly the BT DSLAM May see this as a fault causing your problems leaving the router connected over a few weeks the speed my increase.

[#10]

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@lowden wrote:

When I Googled, I found statements that lower than 10dB was poor, but evidently there's more to it, and I wasn't interpreting them properly.

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I suspect that this predates DLM.