Siemens HIPATH 8000 - Manual (Page 15)

General information
15
Single-line telephone/multi-line telephone
Your OpenStage is a "multi-line telephone" . This means that multiple lines
can be configured, which is not the case with single-line phones. Each line
is assigned an individual phone number which you can use to make and
receive calls.
The programmable sensor keys function as line keys on multi-line phones
page 26.
The "Overview" tab on the telephony interface provides information about
the lines configured on your phone and the current status of each line
page 42.
When using a multi-line phone to make and receive calls, certain particu-
larities must be taken into account
page 127.