AT&T user manual Expanding the 955 System, Line Groups, Private Lines

EXPANDING THE 955 SYSTEM

When you combine two or more 955 phones you create an interacting system where phones share lines. You can have up to twelve phones and up to 15 telephone lines. The 955 can be expanded with or without Centrex service.

NOTE: All 955 features work as described earlier in this manual.

Line Groups

When phones share lines, Line-in-use lights let users at different extensions know when a specific line is in use. For accurate Line-in-use lights, the same lines must be connected to each extension in the Line Group, and they must have the same incoming telephone number at each extension.

The chart below shows 12 extensions, each sharing the first three lines, but being assigned to different Line Groups based on other shared or private lines.

Lines in System

		L1	L2	L3	L4	L5	L6
	ICM 11	✔	✔	✔	✔
	ICM 12	✔	✔	✔		✔
Stations	ICM 13	✔	✔	✔	✔
	ICM 14	✔	✔	✔		✔
	ICM 15	✔	✔	✔	✔
	ICM 16	✔	✔	✔		✔
Intercom
	ICM 17	✔	✔	✔	✔
	ICM 18	✔	✔	✔		✔
	ICM 19	✔	✔	✔	✔
	ICM 20	✔	✔	✔		✔
	ICM 21	✔	✔	✔	✔
	ICM 22	✔	✔	✔			✔

EXPANDING THE 955 SYSTEM

Private Lines

You can use the fourth line on each station as a private line. A private line is a telephone number assigned to just one extension.

NOTE: You must program the lines you are using at each extension so that the system knows which lines are shared and which are private (you cannot physically wire lines with different telephone numbers into each unit for Line 4).

The chart below shows 12 extensions, each sharing the first three lines and having its own private line.

Lines in System

L1

L2

L3

L4

L5

L6

L7

L8

L9

L10

L11

L12

L13

L14

L15

ICM 11

✔

✔

✔

✔

ICM 12

✔

✔

✔

✔

Stations

ICM 13

✔

✔

✔

✔

ICM 14

✔

✔

✔

✔

ICM 15

✔

✔

✔

✔

ICM 16

✔

✔

✔

✔

Intercom

ICM 17

✔

✔

✔

✔

ICM 18

✔

✔

✔

✔

ICM 19

✔

✔

✔

✔

ICM 20

✔

✔

✔

✔

ICM 21

✔

✔

✔

✔

ICM 22

✔

✔

✔

✔

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