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No BT Master socket

frankandliz
Grafter
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Registered: ‎27-04-2019

No BT Master socket

I have just moved from ADSL to FTTC and it has prompted me to look for the Master socket in case I need to carry out any diagnostic testing.

My incoming line to the (1980s) property has a non NTE5 socket, it's really looking in a sorry state, I believe it to be an LJU1 type socket.

So will this existing socket need replacing?  If so how do I go about getting this done?  Do I have to get it done by PlusNet or BT?  Most important who will pay for it and what is the likely cost?

The telephone cable internally looks pretty rubbish is very brittle and has a junction box joint part way along it.  This has prompted me to consider replacing the whole cable with ethernet, any thoughts on that? 

The current speed showing on my online speed tester is on getting around 39 to 40 Mbps, When I was on ADSL I was getting 17 to 20, I was expecting more?  I have only been on the new system for 10 days and perhaps it is still 'learning'? 

My guaranteed speed is 44 Mbps.

Any thought and comments much appreciated. 

23 REPLIES 23
JSHarris
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Re: No BT Master socket

Telephone cable has a different impedance to the cable used in networking.  The normal indoor telephone cable is CW1308, plenty of places sell it, like ebay etc.

 

All the cable inside your house, from the junction box or master socket where the incoming Openreach cable terminates, is your responsibility, rather than that of Openreach.  Not hard to replace this cable though, there are several outlets selling kits with everything you might need.

Baldrick1
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Re: No BT Master socket

@frankandliz 

Looking at https://kitz.co.uk/adsl/btsockets.htm there are two types of this socket. Take the cover off and look inside. If there’s components as well as the test socket then this is the Master and can be used for testing, be it difficult to remove any extension wiring. If there’s no components then it’s an extension and you need to look elsewhere for the Master. Can you post photographs of the interior?

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frankandliz
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Re: No BT Master socket

The junction box is about half way between the where the cable enters the property and where my router is, looks like it was cut and rerouted at some stage and joined together again.

I won't be using the phone cable for a phone as the phone was 'disconnected' when I made the switch to fibre, just thinking would it be better to replace the old phone cable with cat5e and reroute it to where my router is?

JSHarris
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Re: No BT Master socket

As I mentioned above do not use network cable, it has the wrong characteristic impedance, use phone wire, like CW1308.  The difference between the two is the twist rate of the pairs, phone cable has fewer twists per metre so that the impedance matches that of the cable coming into the house.  People have used network cable, but there will always be an impedance mismatch between that and the incoming Openreach cable, and that mismatch may well impact performance.

 

The mismatch is significant, phone cable has about a 600 ohm characteristic impedance, network cable has about a 100 ohm characteristic impedance.

 

CW1308 isn't expensive and is easier to run than network cable anyway, so there are zero downsides to using it.

Baldrick1
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Re: No BT Master socket

@frankandliz 

As has been stated, the answer to your question is No.

Also be aware that regulations dictate that you must not touch wiring upstream of the BT Master Socket. It's your choice but to comply you should contact Plusnet and get them to arrange for Openreach to rewire and fit a proper Master socket. The snag is that I think that they charge about £160 to do it.

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dvorak
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Re: No BT Master socket


Moderators Note


This topic has been moved from Broadband to Everything Else

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frankandliz
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Re: No BT Master socket

Thanks for your reply Baldrick

Can you say who I need to contact at PlusNet to facilitate a new Master socket please.

Looks like I'll just have to suck up the cost!

Once I get an up to date socket I will start on getting the old phone wire removed and get someone knowledgeable replace with Cat 5e or new phone wire.

I have attempted to post pics, hope you can see them and can agree the current box is ancient and needs a replacement!

Thanks for your comments.

 

frankandliz
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Re: No BT Master socket

Thanks JS

I'm afraid I don't have the knowledge to really understand your reply.

Are you saying not to use cat5e? Lots of Googling seem to suggest using it in place of phone wire?

Baldrick1
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Re: No BT Master socket

@frankandliz 

A correction to my earlier post, I understand that the ban on modifying the wiring upstream of the master socket is written in the supply contract, not regulatory. 
You have no master socket, just two extensions, presumably coming from the rats nest labelled innards.

My advice would be to ring Plusnet customer services and get the incoming BT cable rerouted to where you want the master socket and scrap all the existing extensions. The router should be located next to the master socket and any new extensions wired off the master filtered output.

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bmc
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Re: No BT Master socket

@frankandliz 

Do you have any extensions connected? If not you may be able to get the Master Socket moved to where your router is. For FTTC you cannot use Cat5e cable for the connection from the MS to your router.

 

Brian

Dan_the_Van
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Re: No BT Master socket

@frankandliz 

If you are not achieving the Minimum Guaranteed Speed (MSG) then a fault needs to be raised for investigation. Hopefully Openreach would install a Master Socket 5c without the need for payment

 

Mr_Paul
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Re: No BT Master socket

@JSHarris 

"People have used network cable, but there will always be an impedance mismatch between that and the incoming Openreach cable, and that mismatch may well impact performance.

 

The mismatch is significant, phone cable has about a 600 ohm characteristic impedance, network cable has about a 100 ohm characteristic impedance."

Whist I agree with the theory behind your post, do you have any practical experience of it?

I used to work at BT, and when I joined the Outside Broadcast division in the late 1980s, I was on the team that supplied radio broadcasters with OB circuits that utilised the same copper pairs as were used for telephones etc and used equalising amplifiers along the routes to increase the audio bandwidth.

Because 600 ohm was the "standard" output impedance of the broadcaster's equipment, probably for the reasons you mention, that is the impedance we usually set our test equipment to.

However, the BBC insisted, (I don't know why), on sending at 140 ohms impedance, (at +4dB), so when providing circuits to them, we had to set up and test at 140.

The BBC were always more tenacious in ensuring that a circuit met the published specs - so if 140 was good enough for them.........!

 

 

 

 

 

bmc
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Re: No BT Master socket

@frankandliz 

I didn't think of this.

 

If speeds are below minimum then OR would need to investigate. Hopefully they would fit a new MS as stated by  @Dan_the_Van  without any charge to you.

 

You can check estimates here https://www.broadbandchecker.btwholesale.com/#/ADSL

 

If wired speed tests are below minimum then follow the Broadband Troubleshooting instructions from the Help / Support pages. Login first so PN know who you are.

 

Brian

JSHarris
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Re: No BT Master socket

@Mr_Paul 

 

You can get away with a lot at audio frequencies, but VDSL carriers vary in frequency from 25kHz up to 12MHz.  I know people get away with using network cable in place of phone cable, but the fact remains that the Openreach line and the Hub are designed to work with 600 ohm lines, and both have 600 ohm internal terminations.  Seems daft to deliberately choose to use  a mismatched cable, especially as CW1308 is usually cheaper than even Cat5e.