System Numbering - AT&T MERLIN LEGEND System Reference Manual

Features

System Numbering

Description
System Numbering is described in
detail in the System Planning Guide.
2-360 System Numbering
System Numbering is the process of assigning extension numbers to
telephones, adjuncts, calling groups, paging groups, park zones, and Remote
Access. When the system is turned on, it identifies the type of module installed
in each slot in the control unit and automatically assigns extension numbers to
the components in exactly the same order that they are connected to the control
unit.
The stations are assigned 2-digit extension numbers starting with extension 10.
If a user needs a specific extension number, it is simpler to connect the user's
telephone to the station jack that is already assigned the requested extension
number than it is to change the user's extension number.
Both the number of digits and the extension numbers assigned by the system
can be changed to individually address a company's needs. For example,
extension numbers can match room numbers.
Any time extension numbers are reassigned, the following must be considered:
Extension numbers can contain digits 0 through 9 in any combination, except
that no code can begin with 0. (0 is a fixed dial code representing the
primary system operator or QCC queue.)
Extension numbers can contain one to four digits and must be unique. If you
assign an extension number with one or two digits, you cannot use those
digits as the leading digits for a longer extension number. For example, if
extension numbers 1, 2, 30, and 40 are assigned to telephones, those
numbers cannot be used as the first number in longer extension numbers
such as 10, 200, 302, or 4052.
Any time an extension number is reassigned, the original extension number
is available for use.
To use any of the reserved system-assigned extension numbers, (shown in
the shaded areas of the figures on the following pages) they must first be
replaced before they can be used for anything else.
The system offers three numbering plans:
Two-Digit
Three-Digit
Set Up Space
Each of the plans allows renumbering of all or selected extensions.