🚀 go-pugleaf

In article <1992Dec16.161901.24782@krfiny.uucp>, jeffj@krfiny.uucp (J. Jonas) writes:

>No, the source of the information is the switch generating the
>SS7 commands.  As a subscriber, you cannot directly control the messages.
>The days of in band signalling are over.

Depends on how direct is "direct". In an ISDN phone, the SETUP message
is generated by subscriber equipment (e.g. a PC), optionally containing
a "calling party number" information element (and a similar subaddress
info element). The 'screening indicator' field of this info element
may take the values 'User-provided, not screened', 'User-priovided,
verified and passed', 'User-provided, verified and failed' or 'Network
provided' (Q.931, section 4.5.10, table 4-10). The Setup message is
certainly carried by SS7 across the net.

If unique caller IDs are to be transmitted for each individual phone 
connected to a PABX (which by definition is subscriber equipment),
there is no other way to do it than having the phone itself or the
PABX supply the ID to the network.

>> Since your phone can transmit to the other line before the phone is
>> picked up, it should be quite easy to implement this.
>
>On what equipment is this allowed?  Certainly no ESS or crossbar that's
>commonly used around here.

On all ISDN phones, and through all switches supporting ISDN. (But I 
agree that it ISDN phones are not "commonly used"!)