Configuration Manager > Overviews > Phone numbering plan
Phone numbering plan
Proceed as follows:
Using the Configuration Manager ( Overviews > Phone numbering plan)
The phone numbering plan shows all of the internal numbers already created and any additional numbers that have been taken from the internal numbering plan:
Subscriber phone numbers
Group numbers
Voice mailbox numbers
Fax box numbers
Phone numbers for door terminals and audio outputs
Short-code dialling numbers
Emergency call and service numbers
Exchange line access numbers (account numbers) for VoIP accounts
Exchange line access number of the PBX
Automatic receptions
Call parking
Internal CAPI dial-in number
Short-code macros
The internal numbering plan of the PBX permits the allocation of 2 to 4-digit phone numbers in the 10-9999 range. Double allocation of a number is not possible.
Using phone numbers with few digits (two or three-digit numbers) inevitably restricts the possible supply of phone numbers with more digits. For  example, if the phone number 12 is assigned, the phone numbers 120-129 and 1200-1299 are no longer available.
* Note: For some functions a 3-digit maximum phone numbers can be assigned because the last position is needed for the function (e.g. door terminal numbers, phone numbers for call parking).
* Note: The exchange line access number on the PBX is 0 in the factory settings; however, this can be changed (Public switched tel. networks > Exchange line request). Note that changing the exchange line access number restricts the phone numbering plan.
* Note: The overview can be viewed and printed ( Print) in the Configuration Manager by opening the page Overviews > Phone numbering plan.
* Note: The phone numbers can be shown in the Total overview or Grouped by type.
* Note: In the overview Grouped by type click for a type to list the configured numbers.