CALLED FILTERED NUMBER
Calling a Called Filtered Number selects an index characterizing the called party, which varies depending on the installation status (see TELESERVICE FILTERING). This index is called the "Filtering index". If it has not been possible to determine a Filtering Index, if it is an external or internal call, it uses the parameters of the entity associated with the calling party, if it is a local call the communication is released.

Directory Number
Call number using the called party and calling party filtering.

Entity Number
This number is used to allocate the call No. to an entity (see ENTITY), in order to:

• determine the installation status and to choose the filtering index accordingly,
• use this entity if it has not been possible to determine the filtering index.

The notion of entity (see ENTITY) is used to distinguish between several companies (or several departments) in the same installation. Each entity includes its own users, attendants, trunk groups, automated attendant, etc; and its own telephone services.
The calls will be directed according to the contents of the call distribution table for this entity (see ENTITIES: Routing numbers). (If the call is directed to an attendant: see also ATTENDANT: entity call presentation key).

Public Rerouting
Public rerouting corresponds to an ISDN service (VN5). This service is offered by the public carrier upon subscription (e.g. used for calls between CCD call centers). In the case of public rerouting, the PBX receives two numbers: the original number and the rerouting number.
The called/caller filter feature offers to select the number to be filtered:
YES: the rerouting number is filtered
NO: the original number is filtered.