[Asterisk-Dev] Re: [Asterisk-Users] Syntax for hiding caller ID but still passing ANI?

[Linus Surguy]

(as a follow up to my own post)

> > It seems that there are two options that block the presentation: 0x23
and
> 0x21
>
> No no! Protocol wise, they are different flags in each nibble. If the high
> nibble is not zero then the number is not for general use. Any number
> presentation block in PRI->SIP conversion should only pass the CLI if the
> high nibble is zero.

Cut and paste from the ITU Spec Q931

Presentation indicator (octet 3a)

Bits
7 6 Meaning

0 0 Presentation allowed
0 1 Presentation restricted
1 0 Number not available due to interworking
1 1 Reserved
NOTE 1 - The meaning and the use of this field is defined in 3/Q.951 and
4/Q.951.

Screening indicator (octet 3a)

Bits
2 1 Meaning

0 0 User-provided, not screened
0 1 User-provided, verified and passed
1 0 User-provided, verified and failed
1 1 Network provided

NOTE 2 - The meaning and the use of this field is defined in 3/Q.951 and
4/Q.951.

Linus