topic Re: Good RJ11 telephone cable? in Full Fibre

Good RJ11 telephone cable?

artfulbodger — Fri, 24 Jul 2015 08:37:06 GMT

Can anyone recommend a good RJ11 telephone cable? I'm trying to find one that can shield against REIN or any other possible interference.
Cheers.

Re: Good RJ11 telephone cable?

Oldjim — Fri, 24 Jul 2015 08:53:28 GMT

As the reason for the question eludes me - why do you want one and how long would it need to be
Note that an extension from the phone part of the filtered faceplate wouldn't have that problem

Re: Good RJ11 telephone cable?

jafreer — Fri, 24 Jul 2015 08:59:10 GMT

I went with a Belkin RJ11 to RJ11 cable "Hi Speed Modem Internet Cable". It uses twisted pairs for better noise immunity and is about 3 or 4 pounds. All the usual suppliers should have it.
Does it improve the connection? I can't be sure but for the cost, it is worth a try.

Re: Good RJ11 telephone cable?

artfulbodger — Fri, 24 Jul 2015 08:59:48 GMT

Because I'm not happy with the cheapy one that came supplied with our Panasonic base station (which shares the master socket with the OR modem). Only a metre long.

Re: Good RJ11 telephone cable?

artfulbodger — Fri, 24 Jul 2015 09:01:42 GMT

Thanks jafreer. But it's the rj11 to bt431a connection that I'm looking for advise on.

Re: Good RJ11 telephone cable?

Oldjim — Fri, 24 Jul 2015 09:03:46 GMT

that could be tricky as all/most of the ones I have seen are equally cheap and nasty

Re: Good RJ11 telephone cable?

artfulbodger — Fri, 24 Jul 2015 09:19:34 GMT

I feared so too, oldjim. Thanks anyway!

Re: Good RJ11 telephone cable?

JasonMassey — Fri, 24 Jul 2015 09:54:18 GMT

tandy sell twisted pair rj11 cable. search for the length you need
http://www.tandyonline.co.uk/high-speed-rj11-dsl-cable-5m.html

Re: Good RJ11 telephone cable?

artfulbodger — Fri, 24 Jul 2015 10:46:34 GMT

Thanks Jason. The twisted pair DSL is what I've got already between the modem and master socket. It's the phone (rj11) to BT socket (bt431a) that I'm after. Unless I'm looking for something that doesn't exist?

Re: Good RJ11 telephone cable?

g1000 — Fri, 24 Jul 2015 11:04:12 GMT

Quote from: artfulbodger
It's the phone (rj11) to BT socket (bt431a) that I'm after.

I don't think 1m of filtered cable to the phone is going to affect your broadband? What aren't you happy with? If you unplug the phone cable from the master socket what improves?

Re: Good RJ11 telephone cable?

artfulbodger — Fri, 24 Jul 2015 11:51:54 GMT

A few months ago I had a specialist REIN engineer confirm there was some interference near the master socket. We tried everything to pin point it, but couldn't really establish its source. Bizarrely at one point it seemed as though the REIN was coming from the OR modem power chord, which happened to be plugged into a power socket right next to the master socket! I moved the power source away, but there was still some untoward levels. He even changed the power chord to a new one but that also seemed to show the same level of activity (which he was really puzzled about!). Anyway in the end we replaced the faceplate with a Mk2, a lift-and-shift was done for me and SNR reset, and everything's worked fine since then (no random re-syncs), and even better with the introduction of G.INP. However he recommended possibly moving the DECT phones away from the router (Asus) / OR modem / master socket setup to improve things generally in future. I was just thinking of possibly trying to replace the phone lead with something better instead of getting rid of the phone completely (the master socket sits in the office - can't really do without a landline in there)?
Before everyone jumps on the bandwagon and says "if it ain't broken, don't fix ... etc etc", but I was just thinking how bad DECT phones can be near a mastersocket/FTTC setup?
Cheers!

Re: Good RJ11 telephone cable?

jafreer — Fri, 24 Jul 2015 11:56:03 GMT

I also think that the supplied cable with the phone should be fine. Reason for this is that all the filtering is done at the master socket. If you have a VDSL extension from the master socket, you would want that on a good quality cable. VDSL2 frequencies run up to 17 MHz, hence the requirement for a good cable. Your phone cable is only carrying phone frequencies (a few KHz), so the supplied flat cable should be absolutely fine.
Just saw your reply about a possible REIN issue. Do you have the means to monitor the errors on your line (for example, an unlocked modem that you can use to monitor line stats)? That would allow you to monitor error rates (FEC is useful to monitor) and then you can change things about and see what has a positive effect.
I had a similar issue with noise from power line networking adapters. I had no idea there was even a problem until I started monitoring line stats. Once I had the stats, I could start to switch things off, move wiring etc, to see what reduced the FEC error rate on the line.
Might be worth considering. What model of modem do you have?

Re: Good RJ11 telephone cable?

artfulbodger — Fri, 24 Jul 2015 12:23:18 GMT

FEC is zero, jafreer. Always has been - never seen it change infact since G.INP came into being (I know it's got nothing to do with REIN, but I'm just using it a yardstick from when I really started to watch things carefully).
Might change the faceplate to a Mk3, can't harm things I guess.

Re: Good RJ11 telephone cable?

JasonMassey — Fri, 24 Jul 2015 12:25:26 GMT

Quote from: artfulbodger
Thanks Jason. The twisted pair DSL is what I've got already between the modem and master socket. It's the phone (rj11) to BT socket (bt431a) that I'm after. Unless I'm looking for something that doesn't exist?

http://www.amazon.co.uk/BT431A-RJ11-telecom-test-adaptor/dp/B000Q8L33E
How about this, then use the twisted pair JR11 cable.

Re: Good RJ11 telephone cable?

artfulbodger — Fri, 24 Jul 2015 12:28:50 GMT

Thanks Jason. But the fewer 'interfaces' you have in a FTTC setup the better. I'll leave things as they are for the time being, and invest in a Mk3 faceplate (the one I've got installed at the moment is a Mk2).
Cheers!

Re: Good RJ11 telephone cable?

JasonMassey — Fri, 24 Jul 2015 12:31:09 GMT

Quote from: artfulbodger
I was just thinking how bad DECT phones can be near a mastersocket/FTTC setup?

I use EcoDECT phones, when a call is not in use the radiation output is zero.
https://www.youtube.com/watch?v=LkXWLdBlo5o
The EcoDECT base station is close to my modem (Vigor 2860n) If there was an issue with interference from the from the phones, then the modem would drop out when a call was made. However I've never noticed any issues with modem connection when a call is made.

Re: Good RJ11 telephone cable?

Anotherone — Fri, 24 Jul 2015 13:34:54 GMT

Quote from: artfulbodger
Before everyone jumps on the bandwagon and says "if it ain't broken, don't fix ... etc etc", but I was just thinking how bad DECT phones can be near a mastersocket/FTTC setup?

Quite understand where you are coming from and wanting to optimise your setup and minimise risk of any interference issues.
You can usually leave the modem side of things alone, but a short twisted pair screened RJ11 cable for the modem can sometimes help if you do have real problems, but without any definite issue I would leave that side alone., except you mention a Mk3 plate, it has an improved Common-Mode filter - not a bad idea.
Some DECT setups do cause issues with Broadband and double filtering them has often cured those issues. Whether you want to try double filtering is upto you, but if you have Caller Display, check it works after you add a 2nd filter. On some rare occasions some filters have been known to mess it up.
There's a couple arrangements you could try here, it depends a bit on where you want to put your base station.
As you already have a filtered faceplate (part of the standard FTTC install) plug a second filter into the socket and then use a single twisted pair BT plug to BT socket extension lead and plug your existing phone lead into that. The disadvantage is that anything undesirable coming from the base station could still "leak" along that length of twisted pair (nothing is perfect). Also your base station has to be one that doesn't need the bell-wire (existing lead a single pair only). Also if it's not a single pair, you have a bell wire involved, which although filtered at the socket, only has a certain level of attenuation of the unwanted signals, but could also be a further radiating source if the bell wire from the DECT is actually used (some do, some don't).
Getting hold of a single twisted pair BT plug to BT socket could be tricky in any event.
A better arrangement would be to plug such a single twisted pair cable into the socket and have the filter at the far end and plug the DECT into that. But the potential benefits (if any) will depend on where you are locating the base station, how long and where it's own lead may be.
As far as the twisted pair cables go, you can get twisted pair BT plug to BT in-line socket but they aren't that common, but they will be 2-pair usually. You could then cut off the BT plug and crimp on another using the blue pair on pins 2 & 5 only.
You can get single twisted pair RJ11 plug to RJ11 plug, but you need to ensure the one you get has the correct 2 pins in use at the base station end and assuming it doesn't need the bell-wire. You can then cut off the plug at the other end and crimp on a BT plug again using only pins 2 & 5.
The other option you could consider is an extension phone socket wired to the faceplate with CW1308 twisted pair cable (blue pair only) and a filter plugged into the extension socket to give the double filtering and local bell wire in case the DECT needs it.
Hope that's of some help.

Re: Good RJ11 telephone cable?

jafreer — Fri, 24 Jul 2015 18:30:10 GMT

Excellent advice from Anotherone, but you mentioned a REIN issue but you see zero FEC errors. Would you not expect to see some FEC errors if there was a REIN issue?
You could look at the tone graphs to see what frequencies are being used. If you are getting close to the 78 Mbps (if you are on that product), then all the VDSL2 frequencies are being used. In that case, you might expect to see FEC errors caused by REIN.
Equally, I suppose if REIN were to wipe out a part of the band, that then just isn't used (VDSL2 being highly adaptive), you wouldn't necessarily see any FEC errors because that part of the band is no longer being used to carry any data? However you would see that as a gap in the tone graphs. For example, I am far enough from the exchange that some of the higher frequencies just aren't used at all, and so I see that in the tone graphs.
Not sure of the answer myself, but just thought that you might be able to see the effects of REIN by looking at the error rates.