obi100 won't ring phone on incoming calls

[Geoffster]

Hello all,

I've just bought an OBi100 here in the UK. I manually configured the device to work with Sipgate.  I only changed the settings necessary for it to work with Sipgate.

Outgoing calls no problem. Incoming calls don't seem to ring standard UK phones.  I've tried two now with an appropriate adapter "BT socket to OBi100".  If I pick up the incoming call it is actually there but the phone doesn't ring so there's no way of knowing.

Anyone got any ideas how I might troubleshoot this one?

Cheers

Geoff

[ianobi]

Hello Geoff - welcome to the forum.

In most of the world the telephone is a two-wire device. However, here in the UK we like to be different   

A lot of UK phones are three-wire devices. You need an adapter with a capacitor to direct the ringing to the third wire in the phone. Like this:

http://www.maplin.co.uk/p/telephone-to-rj11-adapter-with-capacitor-vd36p

Look carefully at the "BT" style plug on the end of the phone lead. Does it have three pins? If so, then the solution above should work.

There are many other settings to get the ringing exactly right to suit UK phones, but none of them should stop the phone ringing.

[Geoffster]

Thanks a lot for that.  I'll order the Maplin adapter right now and see if it works. Top man, definitely worth a try.

The two phones I have both have 4 metal contacts on the plugs.  At least one of them worked and rang well with a Cisco voip box I have....?

Geoff

[ianobi]

Four pins is normal for a traditional UK corded phone. Two pins will be the line (-ve & +ve, sometimes called A leg and B leg), one pin will be the ringing wire and the fourth pin is for an earth supply to the phone (needed in some old PBX systems for recall).

I can't explain the Cisco voip box, unless it was designed for the UK market. Just now there is a mix of devices around. My dect phone base (branded British Telecom) is two-wire and works fine. Most modern devices will be two wire and are designed to work on UK systems.

[Geoffster]

Ianobi,

Great.  That information is really helpful.  Thanks for taking the time to reply to me. I've ordered 2 Maplin adapters.

I did try the Obi100 with our Dect phone and it did ring it. I've just checked the BT plug on the DECT base station....just 2 metal contacts.  Exactly as you suggest.

So if I can find some ordinary cabled phones with 2 wires perhaps I won't need the Maplin adapters?

Cheers

Geoff

[ianobi]

So if I can find some ordinary cabled phones with 2 wires perhaps I won't need the Maplin adapters?

Yes, the Maplin adapters I suggested are only needed for the older style 3-wire phones, although they will do the job of adapting US to UK plug styles for 2 or 3-wire phones.

If you only have two wire devices plugged into your home phone wiring, then you might want to consider removing the third wire as shown here:

http://www.filesaveas.com/jarviser/bellwirenutshell.html

The OBi and your dect phone base are two wire devices.

The third wire is unbalanced being only one half of a twisted pair, so it can pick up "noise" from other sources and slow down adsl. If you go down that road you need to remove it from each of your home phone sockets.

[Geoffster]

Ianobi,

Thanks again.  I've just received the Maplin adapters and both my phones will ring now. Great. 
You've saved me a lot of time wading through websites and not quite finding what I want!

From your last post I see there's a little more to this VOIP phone lark than just buying a VOIP box.  I'll read the article you mention. If I can't make sense of it I know where to come for expert help :-)

Cheers

Geoff

[Geoffster]

Ianobi,

I'm planning to set up a small office with two quite separate numbers using VOIP phones.

I'd like to site the VOIP boxes near the router (my preference, keep the techie gear in one place) but I have noticed background noise on the line when a longer run to the phone is used. Do you think this noise might be 'induction on the third wire' that you mention?

If I site the VOIP boxes at the desk (and ethernet extends to the OBi100 from the router) the line is then satisfactorily quiet, it's only the captive cable attached to the phone between the phone and OBi100.

I realise I'm shamelessly asking you for info :-)  Don't worry if you've got a lot of ironing to do!

Geoff

[ianobi]

but I have noticed background noise on the line when a longer run to the phone is used. Do you think this noise might be 'induction on the third wire' that you mention?

If you are using the existing house phone wiring, then the most likely cause of induced noise is the third wire problem. This does not just affect voip. It can induce noise into normal corded phone extensions and can slow down adsl performance. Extra-techie explanation is here:

http://www.filesaveas.com/jarviser/broadbandspeed.html

Some people have reported a doubling in their broadband speed after disconnecting the third wire. The increase in speed may take up to two days to happen as the modem in the BT exchange takes time to sample and "retrain" up to maximum speed.

[Geoffster]

Ianobi,

Thanks a lot for your continued attention. Much appreciated.

Our house is wired throughout using Cat6/7 ethernet cable. The cable has an overall shield and each of the 4 pairs is also separately shielded.  These cables are in a 'star' configuration. At the heart of the 'star' is a data cabinet which contains a BT hub, a gigabit switch, NAS drive, and a Satellite TV/Freeview/FM distribution amp.  The BT telephone line arrives here and an adsl filter is also sited here so that the telephone landline may be distributed freely round the house without any individual filters in the rooms being needed.

The cable is terminated in suitably shielded ethernet sockets at both ends. It's this cable infrastructure that is used to distribute ethernet, telephone lines and even analogue audio.

If I site a VOIP box in this cabinet then I can distribute it's phone output using the star ethernet infrastructure to whichever room I want. An ethernet to BT socket adapter in the destination room provides the socket for the phone to plug into. It's this setup that puts noise on the line. There's kit in the data cabinet that will probably be radiating stuff.  I wonder if that's the problem?  So I have been siting the VOIP boxes in the rooms away from the data cabinet.  That removes the background noise.

I haven't got round to troubleshooting by switching off gear in the data cabinet yet.....

Any comments welcome!!

Cheers

Geoff

[ianobi]

Your house wiring is certainly way better than average! In your case I doubt that you have the third wire problem.

Ignoring voip for the moment, if you connect a normal corded phone in the destination room and connect it directly through to the BT line, press any digit to get rid of dial tone, do you hear any background noise? If yes, then the induced noise is getting into the cable either from the data rack or from an external source. If no, then noise is being induced into the OBi box within the data rack.

It could take a while to isolate the cause. Turning off all equipment in the data rack, then turning it on one at a time would prove that side of things. It would be interesting to site the OBi in the data rack and have only it and the router turned on, then plug a phone directly into the OBi in the data rack, then patch it through to the destination room and plug the phone in there.

It's all a matter of elimination! There have been cases of the OBi power supply inducing noise into the OBi itself, but I doubt if that's the case here as you say it's quiet when the OBi is in the destination room.

[Geoffster]

Ianobi,

Thanks a lot for that.

I will experiment and see what I can eliminate.

Cheers

Geoff