B.15. CallingPres()

Changes the caller ID on an ISDN-PRI channel.
Changes the presentation parameter in the caller ID for calls using Q.931 PRI connections. These parameters should be set before the call is initiated. The presentation parameter presentation defines first whether the called party will be sent caller ID information in the first place, and second, whether it was verified against a reliable source (screening).
This application has been superceded by SetCallerPres(), which is easier to use and less dependent on Zaptel.
This application generates a number based on the presentation and screening settings. The meaning of the values themselves is defined in the ITU Q.931-Standard as described in the following tables.
Screening is set by bits 1 and 2:
00The caller ID information was provided by the endpoint and no verification was attempted.
01The caller ID information was provided by the endpoint and was successfully verified.
10The caller ID information was provided by the endpoint but verification was unsuccessful.
11The caller ID information was provided by the network.
Presentation is set by bits 6 and 7:
00Display of caller ID is allowed.
01Display of caller ID is not allowed.
10The number is not available because it was not passed by an intermediate station.
The bits 3, 4, 5 and 8 should be zero (0). Note that the bits are numbered in descending order, i.e. 87654321.
; set presentation to:
; presentation allowed                                                    (00000000)
; provided by the network                                                 (00000011)
; ------------------                                                      ----------
; Result: 3 (bitwise AND)                                                 (00000011)
exten => 123,1,CallingPres(3)
exten => 123,2,Dial(Zap/g1/1234567)
; set presentation to:
; presentation restricted, blocked by intermediate station                (00100000)
; user provided ID, verified                                              (00000001)
; ------------------                                                      ----------
; Ergebnis: 33 (bitwise AND)          (00100001)
exten => 124,1,CallingPres(33)
exten => 124,2,Dial(Zap/g1/1234568)