The line identity is made up of the following information units:
-
The subscriber's international ISDN/MSISDN number;
-
Optionally subaddress information.
For mobile originated calls, the ISDN/MSISDN shall always be provided within the network. The subaddress shall only be included if it is provided by the user (or user equipment).
The calling line identity is the line identity of the calling party. The connected line identity is the line identity of the connected party.
The additional calling line identity provides additional line information for the purpose of the calling line identification presentation service (CLIP). The additional connected line identity provides additional line information for the purpose of the connected line identification presentation service (COLP).
For mobile originating calls the user (or user equipment) has no possibility to provide an additional line identity. For mobile terminating calls the user (or user equipment) has no possibility to provide an additional connected line identity.
In addition to, or instead of, the line identity or additional line identity, the network may send a presentation indicator (PI) together with a Cause of no CLI (CoNC) and/or a screening indicator (SI) to the MS as follows:
-
Presentation Indicator:
-
Presentation allowed;
-
Presentation restricted;
-
Number not available.
-
If the Presentation Indicator indicates "presentation restricted" the Cause of no CLI may give a diagnostic:
-
Unavailable;
-
Rejected by user;
-
Interaction with other services;
-
Coin line/ Pay phone.
-
Screening indicator:
-
User provided, verified and passed;
-
User provided, not screened;
-
network provided.
The screening indicator applies to the ISDN/MSISDN or the number given as additional line identity respectively.