Networks Any telecomms engineers in? [Update - Aug 2011 Broadband Problems]

I have a quick question regarding a BT phone extension for anyone who is proficcient in this sort of thing. I'm not too bad with this sort of networking but I've never set up a line like this before and am wondering if it can be achieved.

I have an analogue phone extension that I want to convert from a BT socket to a CAT5 faceplate/module. This is to get rid of the BT faceplate so that I can have the phone extension on a 4x RJ-45 faceplate. Is it possible for me to connect the three strands from the back of the BT socket to three of the 8 on the back of the RJ-45 module and use an RJ-11 cable to connect the phone to the CAT5 module? My main concerns with this are: 1) I don't know which terminals on the CAT5 module to connect the BT line to. 2) This will leave the extension un-filtered which will cause problems with the broadband connection which shares the same phone line that the extension comes from.

Another way to do it might be instead of using a straight RJ-11 to RJ-11 cable between the phone base station and the CAT5 faceplate, use an RJ-45 to BT socket converter and then filter that.

I'd really appreciate some thoughts on this. IIRC someone here said they were a BT engineer a while back but I can't be sure. Thanks in advance!

 

its all about the pin-out

you just need to be sure you match the pin-out on each end

take a look at this site wich explains the use of each pin acording to the BT standard

http://www.wppltd.demon.co.uk/WPP/Wiring/UK_telephone/uk_telephone.html

as the line comes color coded, its easy to determine wich color goes in wich pin and you just make sure it match the ones needed from the end of the phone

 

Yep, but now I need a pin-out for the CAT5 faceplate as well, so that I can match the wires from the BT extention line to the RJ-45 faceplate. It's quite complicated, and I have to admit I'm afraid I'll blow the phone line if I connect this wrong.

 

you need to match the wires thinking always in the pin-put of the phone, let me ask you, its the line color coded from the wall??

 

Yeah, the phone line coming from the wall is colour coded - Blue, Blue & White, Orange, Orange & White etc.

 

Ok, i was doin some more research about the BT standard, getting rid of the wall BT socket could be a problem

I assume you have a NTE5 plate, you cant remove the top-half of the plate (where the mains from the wall come)

So now i have some confusion with what you want to achieve.

If you plan to get rid of this NTE5 plate, you cant, the top-half its where the pair of mains are and its reponsability of the BT company.

Or is making an adapter from rj45 to BT socket what you want to do? like a 4 socket rj45 faceplate from your room, one of them goin to the BT socket in other ROOM? THIS I THINK WE CAN DO

I working on a diagram of the possible solution, i'd apreciate if you coulkd provide me the pin-out of your Phone (i see the BT standard actualy uses 3 wires, two for speech ring and one for ring, need to know where this goes, i will do my part looking for this info)

BTW, im assuming your phone its RJ11

 

Hi Unicorn, you'll have to get a RJ45 > BT balun to use an analogue phone on an RJ45.
reason being is the extra components on the back of the BT socket are normally used to generate the rining.

I wired up where i work with Cat5e throughout,
The PBX extentions run off RJ45 crimped instead of BT plugs but those phones are digital so they don't need the extra bits, the analogue stuff like faxes however need a master socket balun so they can ring.

you should still only need the center pair for the extention with a master balun, you can drop the bell wire. (unless you find it doesn't ring)

 

Ok, I have one of those... Actually, I have about 100 of them, left over from when we wired up the digital phone system in the last office building we networked. So that's no problem. There are no extra components on the back of this particular BT socket that generate the ringing... as I've said before, this is an extension. It's just a standard BT slave socket.

Ok, now we're getting somewhere. I need the center pair, this I actually already knew. The third wire was confusing me greatly. What colour should these two wires be, or what position should they be in on the BT slave socket? Are they in the center on a "BT" plug as you've said, the same as they are on an RJ11?

I still don't know which two IDC terminals to use on the back of the RJ45 module though, which is where the confusion started off for me. I'm using Excel CAT-5E modules and faceplates, and the mastered tailed adapters (baluns) I have are Excel also.

So, as far as I can see it should be:

Phone extension wire --> RJ45 module --> RJ45-BT Balun --> BB Filter --> Phone base station.

Correct?

 

You could just go.
BTsocket - btplug-btplug lead - modtap - rj45 then modtap - adsl filter/phone.
Works for us in the office send analogue lines over RJ45 for faxes

 

I'm trying to get rid of the BT faceplate though, and put the phone connection on a 4x RJ45 faceplate (along with 3 ethernet connections from CAT5 patch) whilst not changing any cables... I'll be putting phone cable into the back of an RJ-45:

 

Just remember to clearly mark that socket.
Running phone voltage in to a nic would not be fun (or you could just use a modular faceplate & put 3x rj45 & 1x rj11 in it)

 

Well that sounds nicer and a lot easier... They are modular faceplates that I use anyway, the Excel ones are hard to beat. I might just do that instead... although doesn't using RJ11 bring back the problem of introducing an unfiltered phone on the line?

For the record, it would be very clearly labelled, and it's in my own workshop anyway, so nobody else would be near it

 

Hang on - do you actually need a phone in this socket, or just a filtered RJ11 socket for ADSL? I know you said about a phone socket but I wasn't sure if you need the phone too.

Cos if you grab a NTE-5 faceplate filter and steal the gubbins, there's a 2-pair filtered data-only blue terminal inside, which could be terminated on a RJ11 faceplate.

 

Sorry if i miss-understood anything, was still tired this morning.
most balun's i've seen use the center pair on the RJ45, so that'd be pin 4 & 5.

Zoon's idea is probably a good one,
i know some of the 3rd party master socket filter faceplates had both a filtered and unfiltered punchdown pairs on them, i needed this for my router as it's running off an extention.
Think i got mine from solwise though i'm not 100%.

if it's got a filtered pair, punch that down and run it to 4&5 on your rj45 faceplate, i'd trial and error it on the phone, if it doesn't have a tone, swap the pairs so they're 5&4.

failing that, break one of the balun's open and trace the cables back to the plug.

 

Nope, it's for the cordless phone in the workshop mate - internet access is all done through the network down there (I must get that network diagram uploaded and post it in my server thread for you later by the way )

I may have to crack a balun open, although using the center two makes sense (4 and 5). As far as I know, my extension socket doesn't run from a filtered pair, as every other extension in the building has to be filtered as well as this one (if that's what you mean) and I know for a fact that it's a 9 year old BT master socket which was installed when the house was built.

 

two center wires from the RJ11 --> RJ45 JACK, here you need to wire the 4 & 5 pins (they're color coded too, so 4 & 5 are the white/blue & blue) this wires must go to the 2 & 5 pins of the BT EXT jack.

 

You could rip out your extension, and replace it with a Cat5e straight through from beside your master socket, then do a balun on either end with a cable to your master socket?

That might be overengineering it, but I know for sure that Cat5e straight through sockets with baluns can carry analog phone lines, as that's how every company I've been with has pushed fax or modem lines through.

 

It took me two full days to get a CAT6 cable fished from my router in the house down to the workshop - it's not happening again To give you an idea - I used almost 70' of cable to do that.

Is what paisa said right? 4 and 5 on the RJ45 to 2 and 5 on the BT jack

 

2 & 5 ring a bell (pardon the pun) in my head,
just googled it and low and behold....

http://www.wppltd.demon.co.uk/WPP/Wiring/UK_telephone/uk_telephone.html

and http://en.wikipedia.org/wiki/BS_6312

2 & 5 should be your ring and tip, with 3 being the bell wire
(which is defunct and can act as an arieal, degrading the adsl signal)

Good work Paisa, and sorry it took me so long to post a link.

 

hey.. here to help