AT&T MERLIN LEGEND Key System Planning page 50

Control Unit
Three Digit Numbering
Plan
2-20
System Numbering
The unshaded areas of the two-digit numbering plan in Figure 2-3 indicate the
extension numbers available for reassignment. This means that you can change
selected extension numbers to one of the available numbers, for example,
extensions 6886 through 6899. If the available numbers shown do not meet your
needs, consider the three-digit numbering plan.
Planning Form Instructions
Use Figure 2-3 as you record extension number information.
1.
If the system includes digital station adjuncts.
Locate Key System Form 2b, System Numbering — Digital/ISDN
Station Adjuncts.
Write the 3 digit extension number — the extension number from Form 2a
with a "7" preceding it — in the "Factory - Set Extension No." column of
Form 2b.
2 .
If you do not need to renumber any of the factory - set extension numbers:
Check the "2 - Digit" box under the "Renumber To" heading on Form 2a.
Go to the "Form and Floor Plan Update" instructions later in this
chapter.
3 . If you want to renumber only a few of teh extensions, and enough
numbers are available.
Check the "2 Digit" and "Selected Extension Numbers" boxes under the
"Renumber System" heading of Form 2a.
Write the new extension number(s) in the "Renumber To" column on
Form 2a and Form 2b.
Go to the "Form and Floor Plan Update" instructions later in this
chapter.
Figure 2-4 shows the numbers automatically assigned by the system when you
renumber with the three-digit numbering plan. The numbers in the figure are
arranged in blocks according to the first digit. The type of equipment or feature
to which they are assigned is shown in the block.