esupg@cu.warwick.ac.uk (barj) (01/25/91)
Recently, I have seen some equipment for sale in the UK that displays
the caller's telephone number before you answer the phone. How is this
done? I think I read in this group a little while ago that in the US,
the caller's phone number comes down the line (in DTMF) between rings.
Is this true? Is a similar system used here? Is it automatic or (more
likely) do you have to pay BT (or Mercury) lots of money to get it?
Any information - please email or post.
Sorry if this is a FAQ, but I haven't seen it here.
Thanks in advance.
esupg@uk.ac.warwick.cu
Andrew University of Warwick, Coventry, UK.
Bargery 154 Brunswick St, Leamington, CV31 2ER, UK.
vox : +44 926 881264
[Moderator's Note: Where Caller*ID is available here, it is
transmitted between the first and second ring. If you were monitoring
or tapping the line when a call arrived, you would hear the data as it
arrived on your end. I do not know precisely what system you have
there, but I know enough about British Telecom to know they don't send
it to you for free. :) PAT]steveh@relay.eu.net (Steve Hamley) (01/29/91)
Andrew Bargery (esupg@cu.warwick.ac.uk) writes... > Recently, I have seen some equipment for sale in the UK that displays > the caller's telephone number before you answer the phone. How is this > done? I think I read in this group a little while ago that in the US, > the caller's phone number comes down the line (in DTMF) between rings. > Is this true? Is a similar system used here? Is it automatic or (more > likely) do you have to pay BT (or Mercury) lots of money to get it? The piece of equipment that you describe is a rip-off. Neither BT or Mercury send Caller*ID information over normal analog circuits and seem unlikely to do so in the future. The company who market the device are very cagey about admitting this. If you want to know who's calling and you're on a System X exchange then it is possible to convert to ISDN. Alternatively, 'Distinct Ringing' will soon(ish) be on the way as an extra 'Star Service'. The Caller ID device being advertised works as follows. When a person calls your number, it answers the call and asks the person at the other end (in a badly digitised voice) to key in the number they are calling from. It then displays this on a small LCD display. You then have the option of answering the call if the number is one you recognise. The flaws of such a system are rather obvious. Not least the fact that only around 10% of UK residential phones use DTMF signalling, which the device needs to take down the caller's number. **** As a brief comment on another message in the Digest, CNN's Peter Arnett isn't the only Western reporter left in Iraq. Alfonso Rojo from Spanish newspaper El Mundo is also permitted to remain by the Iraqi authorities.