On Sun, 19 Nov 2006 10:57:03 GMT, "John"
wrote:

My daughter wants a new DCT phone and would like caller identification. Been
reading up and it appears that many types of calls do not display the
caller. Is this a fact?

Yes, many calls using third party handlers such as 18866 or VOIP
originated calls will not show caller ID (and in some cases
misleading information like "overseas"!).

Some places which have a single incoming number, such as Doctors
surgeries, often withhold caller ID on outgoing calls from other
numbers. They could show something called a presentation number but
few do.

Some sales organisations show withheld or completely garbage numbers
(the latter invariably because of badly configured systems rather
than malign intent).

Do they only display names where the number and name has been programmed in
(like with a mobile?)

Yes.

or do they display all numbers?

Where number information is provided by the exchange.

Is it reliable?

What do you mean by reliable? For all practical purposes it cannot
be spoofed, so if 01442 123456 is displayed the call will be coming
from that number or that organisation (if it is a presentation
number). A normal caller cannot fool CLID (although VOIP originated
calls can appear to in some cases).

Will it display all numbers - no, as many calls don't include number
information.

Is what it says correct - no in that indirect calls and VOIP calls
may show as international when they are local (this isn't a fault -
the indirect carriers and VOIP suppliers find it cheaper to route
calls via overseas links at certain times of the day).

Be aware that if your phone service is provided by other than BT some
cable operators exchanges still use a different CLID system to the BT
one so make sure you get a phone which suits the system you have.

However, as it is free and as nearly all DECT phones incorporate it,
it is worth having. Don't forget you do have to ask for it to be
activated on the line.

--
Peter Parry.
http://www.wpp.ltd.uk/