communications (DID) A service offered by telephone
companies which allows the last 3 or 4 digits of a phone
number to be transmitted to the destination
exchange.
For example, a company could have 10 incoming lines, all with
the number 234 000. If a caller dials 234 697, the call is
sent to 234 000 (the company's exchange), and the digits 697
are transmitted. The company's exchange then routes the call
to extension 697. This gives the impression of 1000 direct
dial lines, whereas in fact there are only 10. Obviously,
only 10 at a time can be used.
exchange at the end of the 234 000 line, a computer running
fax server software and
fax modem cards uses the last three
digits to identify the recipient of the fax. This allows 1000
people to have their own individual fax numbers, even though
there is only one 'fax machine'.
(1997-06-29)