Snom VoIP Phone - Manual (Page 7)

Installation
7
If you want to use a headset, it can be connected to the audio jacks on
the rear side of the snom 220. The connector named “In” is for the
microphone.
Keypad
The numeric keypad with the keys 0 to 9, * and # is used to enter digits
and letters. Depending on the operating mode, different actions can be
performed (see the table below):
Entry of digits only (e.g., when dialing a phone number),
Typing in letters and digits by pressing the keys repeatedly (similar to a
cellular phone).
The MENU key
is used to invoke the main menu. To cancel
actions or input, the CANCEL key can be used. The ENTER key
confirms actions, selections and inputs.
Depending on the operating mode, the keys can have context-specific
meanings which are described in this manual.
The soft keys F1 to F4 located below the display are context-sensitive
function keys. Their current mapping is depicted with symbols in the
bottom line on the display.
The five keys on the right with LEDs on them are the programmable
function keys that different functionalities can be mapped onto.
The keys of the numeric block in different operating modes: