withheld number - phone wiring

[Steve]

Ok, something's bugging me.

One phone line. Two sockets. Both sockets say BT on them. Line is, in fact, BT operated. One socket is master and one is an extension, hardwired in, i'm guessing by BT.

Perfectly normal so far.

Two bog-standard BT branded telephones are plugged into the two sockets. One of these phones withholds the number when you dial out. Its the one on the extension. Why does it withhold its number? Is it to do with the wiring?

Is there a way I can un-withhold the number on the extension phone?

 

[plugwash]

have you tried swapping the phones?

whatever it is it sounds unusal, are theese REALLY basic phones or do they look like they may have some level of built in intelligence.

are you POSITIVE they are on the same line?

 

[baldelectrician]

if you dial 1470 before you make a call it will send the caller ID for that one call

 

[securespark]

There are 2 ways to withold a number.

In terms of the line, if the subscriber asks the operator to permanently withold the number, then it will not be given out at all.

If you want to ocassionally withold a number, you can prefix your dialled number with 141.

But neither scenario explains your set-up. I think the other(s) are right - it must be a phone problem.

 

[breezer]

unless the phone is set to dial 141 (as mentioned earlier, is it an intelgent phone)

 

[Steve]

no, as i said, both phones are bog standard phones, made by BT. Just one has an extra-long curly wire on it. Not even any memory numbers on either phone.

Now i think on, i cant recall if the master socket is in the office or at the till. the socket in the office is by the window, but the one behind the till is next to an ISDN linebox, and i seem to remember a wire connecting this ISDN to the phone socket. So either could be master socket.

The 2 phone sockets both share the same line though - they both ring together.

There are 3 other master sockets in that till cupboard - for other equipment, all on different lines (they have the numbers written on them)

 

[RF Lighting]

I dont suppose one of the sockets is part of a small phone network or something simple like that?

 

[Steve]

I dont suppose one of the sockets is part of a small phone network or something simple like that?

not as far as i know. and it is possible to pick both phones up and talk between them (obviously not very clearly) i'm now almost certain that the master is the one next to that ISDN line. Is it possible for a fault to develop on a phone so that it blocks transmission of the outbound number?

 

[plugwash]

a fault is unlikely but if it had enough intelligence it could possiblly be programmed to do so.

have you tried swapping the phones yet? and if so did the behaviour stay with the phone or stay with the socket?

 

[ninebob]

it is possible to pick both phones up and talk between them (obviously not very clearly)

Have you actually tried this with no other call in progress? If the phones are wired in parallel as you suspect, you should be able to pick up both phones, hear the dial tone in each and be able to talk over it to each other.

 

[JohnD]

If one of the phones was on the ISDN line, it might well have been set up to hide CLI, to stop anyone ringing back on it.

Will you give me a hundred pounds if it turns out that the two phones are not on the same line?

BTW is it your Lottery ISDN or your Security ISDN?

 

[Steve]

BTW is it your Lottery ISDN or your Security ISDN?

lottery ISDN. the lotto machine has an ickle modem attached to the front of it.

the way i suspected it is all wired is that there are 2 cables coming in from the pole. one of these goes into the ISDN box. one pair actually goes into the ISDN, and another pair is extended to the phone socket.

the other pole wire goes to the another master socket in the cupboard, and another 2 pairs are extended to the other 2 sockets.

upstairs in the office is another ISDN (now disused), a line for the alarm system, and a line for our broadband connection (just the computer plugged in here).

I'll have a look at the phone when i'm at work tonight, see if i can make any sense of this. But i do know they are both on the same line, and there is no fancy phone network in our shop, just a whole load of phone lines. I'll try to see how many pole drop wires there are too.

 

[JohnD]

lottery ISDN.

The lottery lines are (were?) provided for lottery business only, you may have noticed that you do not get a monthly bill of call charges on it. It is (?was?) part of a different kind of contract with Camel.

I am surprised it has CLI suppression, for different reasons.

 

[Steve]

lottery ISDN.

The lottery lines are (were?) provided for lottery business only, you may have noticed that you do not get a monthly bill of call charges on it. It is (?was?) part of a different kind of contract with Camel.

I am surprised it has CLI suppression, for different reasons.

confused. what i mean is, the ISDN line only uses one pair in the phone drop wire, yes? so they used another pair to feed the phone socket, wired as a different line at the switch box over the road. same with the 3 other master sockets, they use the same drop wire, utilising 3 pairs.