Confusing master socket setup

[#1]

The house that I recently moved into has 2 prefiltered master sockets, one upstairs and one downstairs. The downstairs socket is completely impractical to use so I had assumed that someone had it moved upstairs at some point.

When I moved in, I was with Sky who estimated 29-37Mbps download and I actually received 39/5.5. Switching to Plusnet, they estimated 37-55Mbps download and 8-13Mbps upload, however presumably as I should have expected I am seeing 39/5.5 as I was previously.

I contacted Plusnet to see if they had any ideas as to what was going on and they suggested I try the router on the test socket to see whether that has an impact. Having tried this on both sockets for completeness, I got the following results:

• Downstairs: 32/7.5 (35/7 through faceplate)
• Upstairs: 39/5.5 (same through faceplate)

I don't really understand what is going on here, especially given the higher upload on the downstairs socket. Can someone help me understand?

[#2]

OK so this is very strange, I just took the front off the master socket downstairs and am now receiving 39/8 upstairs.

[#3]

@djrivers 

Is one of them acting as an extension? If the better speeds are upstairs that is likely to be the master. Are there any extensions wired from its front plate? Or, is there a junction box somewhere (inside or on the outside wall) feeding both - which is non standard wiring (star wiring used to be done but no more as you cannot get at a true test socket). 

Have you tested the speeds from the test socket in each location?

[#4]

How would I be able to tell if one was the extension?

I am assuming that the upstairs is the master given I've now managed to get the highest upload speed from it, although I don't understand how removing the faceplate downstairs impacted it.

There is a small grey BT box outside the house and wiring feeds up the outside wall to both sockets.

My speed tests are in the initial post.

[#5]

@djrivers I'm no telecoms engineer, but the previous occupiers must have persuaded the installation engineer to do a totally non-standard and (IMO) dodgy install. For thing to work correctly, your single connection to the 'outside world' should be into the downstairs socket, with an extension to the upstairs. If as you describe, both sockets are 'master' sockets you are going to have a problem.

How old are the sockets - roughly?

[#6]

@djrivers 

If there are wires connected to the back of the faceplate then those wires should feed an extension socket. If you take that faceplate off that disconnects the extension and then there would be no dial tone at the extension, confirming that is the set up.

However, your small grey box sounds like a BT junction box. Now that could be wired in two ways:

1. Star wired to both sockets (the old way and not done in the last fifteen (?) years or more as it means that the test socket in any master is not truly isolated from your home wiring). If you have no extension wiring back of the socket faceplates then it seems as if that is how you are set up.

2 The extension wiring from the master socket front plate is run to that junction box (but to a different pair of terminals from the incoming BT line) and from there to the extension socket. 

[#7]

@djrivers 

When we moved into this house some 30 years ago we got BT to run an extension to the bedroom upstairs. They ran it from the little grey box externally. About 15 years ago I had an issue with my broadband and could not check via the test socket (as the upstairs extension was still connected via that box) and after I reported that to Plusnet thay got BT to come and sort the wring out (they fed the extension wires back from the master socket to different terminals in that box and disconnected the upstairs extension wires from the incoming terminals and reconnected then to the now extension terminals). That was done FoC as it had been done that way by BT originally. However, unfortunately, I doubt that BT will sort that now FoC.

[#8]

---

@djrivers wrote:
There is a small grey BT box outside the house and wiring feeds up the outside wall to both sockets.

---

So is there two wires coming in to the house coming from the grey box? If so then both will almost certainly be connected as Masters. This will introduce a bridge tap, which could well explain this.

In this case one of the wires needs to be disconnected so that there is only one master socket. This should be done by Openreach but this could be chargeable as it is not a configuration that should ever have been installed. Whether you call them in or are prepared to take the cover off the grey box, are handy with a pair of cutters and prepared to take the risk of removing the correct cable is your decision.

[#9]

@Baldrick1 

---

@Baldrick1 wrote:

---

@djrivers wrote:
There is a small grey BT box outside the house and wiring feeds up the outside wall to both sockets.

---

So is there two wires coming in to the house coming from the grey box? If so then both will almost certainly be connected as Masters. This will introduce a bridge tap, which could well explain this.

---

Exactly my thoughts, but I didn't express them very well.

[#10]

Photos of the two sockets with the faceplates off in case that helps: http://imgur.com/a/qgEIkL5

[#11]

Much easier to understand - the top picture is the master socket, the bottom one an extension, so why they are both wired from the junction box is a mystery.

[#12]

What would explain the fact that I've managed to get the best speeds (39/8) from upstairs, with the downstairs faceplate removed (which did interrupt the connection for ~1 min)?

[#13]

@djrivers  rather than a speed test, if you go to the Advanced/Troubleshooting/Helpdesk of the router, and post details of the sync and attainable speeds from both test sockets it should give a better idea of how things are wired.

Speed tests can take longer to move if profiles have been fixed.

[#14]

Poor wording on my part, the speeds I've been posting are taken from the maximum data rate in the helpdesk area.

So for completeness:

• Downstairs:
  • 32/7.5 via test socket
  • 35/7  via faceplate
• Upstairs:
  • 39/5.5 via test socket and faceplate
  • 39/8 with downstairs faceplate removed

[#15]

---

@djrivers wrote:
What would explain the fact that I've managed to get the best speeds (39/8) from upstairs, with the downstairs faceplate removed (which did interrupt the connection for ~1 min)?

---

Possibly - and I am not saying this is correct - because both sockets are wired from the junction box, which is wrong, AFAIK. My understanding is that the extension should be wired from the master socket.