AASTRA 4222 Office for BusinessPhone User Guide EN - Manual (Page 112)

Installation
BusinessPhone – Dialog 4222 Office / Dialog 3211 & 3212 112
Dialog 3212 Standard /
Dialog 3211 Economyplus
Install cables
1 Cable to handset
2 Cable to exchange
3 Space for personal directory list (optional)
4 Wall mounting screw holes
You can put the cable to the handset in any of the two notches
underneath the telephone. The cable to the exchange has to be
plugged in LINE.
Change cables
To remove a cable, push down the plug stop. Use a screwdriver to
unlock the stop.