[asterisk-users] A Caller ID question (UK)

[Gordon Henderson]

Heres an oddity. Call comes in on a ordinary BT POTS landline, and in the
UK, (to my knowledge!) the caller ID can be one of 3 things: The number,
"withheld" and "unavailable" (which usually means an international call
from a non caller-id co-operating telco, or someone in the UK using some
el-cheapo telco to place outgoing calls)

This works OK. On my DECT phones I get the right thing on the display.

Now stick an asterisk box inbetween the incoming line and the DECT
phone,and arrange for incoming calls to be forwarded to the DECT phone.
(TDM400P card)

Now, the display on the DECT phone still displays the right thing - ie.
the number, withheld, or unavailable. But Asterisk internally just gets an
empty ${CALLERID} variable with either withheld or unavailable calls.
(When a number is presented it gets the correct number)

Anyone know how to distinguish between the 2 inside the dialplan? (if it's
at all possible)

Cheers,

Gordon