Slow Max sync rate from master/hidden test socket and extension socket

[#1]

I wonder if someone a bit more knowledgeable than me can give some hints on what's happening here ?

I'm currently synced at 23830 irrespective of which socket I plug the router in to and I'm wondering if it may be down to wiring.
I have DSL filters on all extensions and a quiet line test 17070 is quiet and there are no hisses or crackles.

BTW website would suggest that I'm able to get the following speeds:
Clean: 47.7 (high) 32.4 (low) download / 7.8 (high) 5.5 (low) upload
Impacted: 46.3 (high) 29 (low) download / 7.7 (high) 5 (low) upload
It also says I have a bridge tap and the min/max observed speeds are 24.99 down/6.77 up. VRI is no and NTE Faceplate is no.

BTW speed test gives me a download speed of 20.8 Mbps / 6.4 Mbps upload and an IP profile of 21.98Mbps.

I've also added the router stats when plugged into the master and hidden test socket. Both these show the same sync rate but slightly higher max achievable speed than when the router is plugged into the lounge extenstion (where the max achievable varies between 33000 and 39000).

The attached diagram (telephone_wiring.png) attempts to show the wiring inside and outside my property. The green box is the BT phone junction box outside, and it looks like three cables come out of that box.
The purple line was a second telephone line that is no longer used and has no dial tone (I'd be happy for this to be removed).
The red cable is an external cable outside the house that comes from the junction box and feeds into a telephone socket in bedroom 1. This bedroom 1 socket appears to be an extension-type and doesn't have a test socket.
The blue line is internally wired and feeds into the master/test socket in the kitchen. From this socket, there is a further internal cable that feeds into an extension socket in the lounge (green line), which is where the router is normally placed.

I've done some more testing in the last few days (so that should explain why the connection has been going up and down recently). When the router is plugged into the lounge extension (green line), the max sync rate is 23830. When I plug the router into either the master or hidden test socket in the kitchen, the max sync rate is still only 23830 (but note the max achievable is a bit higher than this). When plugged into the hidden test socket, then there is no dial tone on the lounge extension (green), but there is a dial-tone on the bedroom 1 extension (red). Does this suggest that the line to bedroom 1 (which remember is an external cable) has been tee'd off the other cable at the outside juncion box ? And does it explain why my line says it has a "bridge tap" ?
I've now put my router back into the master socket in the kitchen (as we need the have the phones working in the lounge and bedroom). 

So, to summarise, I'm wondering if the bridge tap showing on my line is due to the external cable being tee'd off the BT junction box and that is what is causing the identical maximum sync rate of 23830 in either of the lounge extension, master or hidden test sockets ?

As both these cables are outside my property is that something BT could look at at no charge to myself ? These external cables have been in place before we moved in and we haven't had any work done on them or touched them ourselves.

I'm also looking at getting an i-plate as I can see the red ringer wire is in the master socket, but until the outside cabling is sorted I doubt that this would increase the sync rate as I'm still only getting 23830 from the test socket ?

I've also raised a ticket with plusnet for them to look at the speed issue and put the above information into it.

Thanks,
Supertux

[#2]

I wonder if someone a bit more knowledgeable than me can give some hints on what's happening here ?

I'm currently synced at 23830 irrespective of which socket I plug the router in to and I'm wondering if it may be down to wiring.
I have DSL filters on all extensions and a quiet line test 17070 is quiet and there are no hisses or crackles.

BTW website would suggest that I'm able to get the following speeds:
Clean: 47.7 (high) 32.4 (low) download / 7.8 (high) 5.5 (low) upload
Impacted: 46.3 (high) 29 (low) download / 7.7 (high) 5 (low) upload
It also says I have a bridge tap and the min/max observed speeds are 24.99 down/6.77 up. VRI is no and NTE Faceplate is no.

BTW speed test gives me a download speed of 20.8 Mbps / 6.4 Mbps upload and an IP profile of 21.98Mbps.

I've also added the router stats when plugged into the master and hidden test socket. Both these show the same sync rate but slightly higher max achievable speed than when the router is plugged into the lounge extenstion (where the max achievable varies between 33000 and 39000).

The attached diagram (telephone_wiring.png) attempts to show the wiring inside and outside my property. The green box is the BT phone junction box outside, and it looks like three cables come out of that box.
The purple line was a second telephone line that is no longer used and has no dial tone (I'd be happy for this to be removed).
The red cable is an external cable outside the house that comes from the junction box and feeds into a telephone socket in bedroom 1. This bedroom 1 socket appears to be an extension-type and doesn't have a test socket.
The blue line is internally wired and feeds into the master/test socket in the kitchen. From this socket, there is a further internal cable that feeds into an extension socket in the lounge (green line), which is where the router is normally placed.

I've done some more testing in the last few days (so that should explain why the connection has been going up and down recently). When the router is plugged into the lounge extension (green line), the max sync rate is 23830. When I plug the router into either the master or hidden test socket in the kitchen, the max sync rate is still only 23830 (but note the max achievable is a bit higher than this). When plugged into the hidden test socket, then there is no dial tone on the lounge extension (green), but there is a dial-tone on the bedroom 1 extension (red). Does this suggest that the line to bedroom 1 (which remember is an external cable) has been tee'd off the other cable at the outside juncion box ? And does it explain why my line says it has a "bridge tap" ?
I've now put my router back into the master socket in the kitchen (as we need the have the phones working in the lounge and bedroom). 

So, to summarise, I'm wondering if the bridge tap showing on my line is due to the external cable being tee'd off the BT junction box and that is what is causing the identical maximum sync rate of 23830 in either of the lounge extension, master or hidden test sockets ?

As both these cables are outside my property is that something BT could look at at no charge to myself ? These external cables have been in place before we moved in and we haven't had any work done on them or touched them ourselves.

I'm also looking at getting an i-plate as I can see the red ringer wire is in the master socket, but until the outside cabling is sorted I doubt that this would increase the sync rate as I'm still only getting 23830 from the test socket ?

I've also raised a ticket with plusnet for them to look at the speed issue and put the above information into it.

Thanks,
Supertux

[#3]

Well, after leaving the router in the master socket overnight, I saw that my line has been up for around 6 hours, and I can see that the sync rate has increased a bit:

Data rate:

4675 / 24968

00:54:25, 14 May.	(39731.120000) PPPoE is up -​ Down Rate=24968Kbps, Up Rate=4675Kbps; SNR Margin Down=13.3dB, Up=6.0dB
00:54:25, 14 May.	(39731.100000) CHAP authentication successful
00:54:25, 14 May.	(39731.050000) CHAP Receive Challenge
00:54:25, 14 May.	(39731.050000) Starting CHAP authentication with peer
00:54:25, 14 May.	(39731.040000) PPP LCP Receive Configuration ACK
00:54:25, 14 May.	(39731.040000) PPP LCP Send Configuration Request
00:54:25, 14 May.	(39731.040000) PPP LCP Receive Configuration Reject
00:54:25, 14 May.	(39731.030000) PPP LCP Send Configuration ACK
00:54:25, 14 May.	(39731.030000) PPP LCP Receive Configuration Request
00:54:25, 14 May.	(39731.030000) PPP LCP Send Configuration Request
00:53:34, 14 May.	(39680.400000) PTM over DSL is up
00:53:00, 14 May.	(39646.810000) PTM over DSL is down after 313 minutes uptime
00:53:00, 14 May.	(39646.810000) PPPoE is down after 94 minutes uptime [Waiting for Underlying Connection (WAN Ethernet 7 -​ Down)]

[#4]

@supertux. Together with our network partners at Openreach we are prioritising customers who don’t have a phone line or broadband connection, meaning there might be a delay in Speed Faults being fixed. In the meantime, please raise your speed fault online at faults.plus.net.

Thanks - Carl

[#5]

@supertux 

The bedroom 1 cabling is a bridge tap but possibly not the only one on what is apparantly pretty obsolete old wiring.

As you are not getting your promised speed when connected to the Test socket this should be sorted, probably by removing redundant cable/rewiring, free of charge by Openreach once they get to you. Your lounge extension is wired correctly.

When Openreach come have tea/choccy bicuits available and ask for a filtered faceplate to be fitted.

[#6]

Thanks for quick response @Baldrick1 .

With a filtered faceplate on the master socket, am I right in saying that this will block vdsl signal to any extension socket, so it would mean I wouldn't be able to have the router off the lounge extension ?  If so, is there any way of getting around that as having the router in the kitchen isn't an ideal place for it (lack of power, risk of spillage, etc) ? 
Is that something the BTOR engineer would be able to do as part of the free of charge work ? 
Thanks,
Supertux

[#7]

@supertux 

To get the best possible speed the router should be plugged in to the Master socket. Yes, with a filtered faceplate you no longer need any dangly filters but only the master socket can be used for the router connection. Theoretically moving the master socket is chargeable but I guess that on the day this comes down to your powers of persuasion.

If you do not want a filtered faceplate and to plug your router in to the lounge extension then forget the filtered faceplate. In this case I would avoid plugging a phone into the master socket.

[#8]

Just phoned Plusnet for an update on my ticket.
I now have an BTOR engineer coming on Monday to sort the external bridge tap out.

Must admit, I was very impressed how quickly I got through to Plusnet on the phone just now, and thanks Danielle at plusnet for sorting the engineer visit out for me. Very happy with the experience, ta.

[#9 · Accepted solution]

Just wanted to give an update.
My slow speed sync rate has now been fixed this morning.
Talked through a few options with the engineer including moving the master socket, laying back cables, etc but ended up doing the following.

The engineer fixed the external extension bridge tap, fitted a master5c socket + VDSL filter on the master socket in the kitchen.
I was also able to ask very, very nicely and the engineer connected the lounge extension 2 and 5 wires to the A and B data extension terminals in the kitchen master socket. I've plugged in a DSL filter in the lounge extension and I now have a working router and phone off that extension.
I'm now also getting a sync rate of 39950 from the lounge extension socket.  Amazing really, as the wiring inside is pretty old alarm wire.
I suppose if the data rate drops, then I always have the option to plug the router into the kitchen socket, and then look at laying some cat5e up to the lounge.
The only downside was the engineer didn't have any new faceplates so had to use a bit of dirty one he found lying about his van, although he did promise that he'd drop a new one round when he's got them back in stock.
Thanks for the guidance and suggestions everyone on this forum.
Supertux.