How to register a Headset to the N720 DECT Multicell-System:

Step 1: Go to Settings --> Mobile devices --> New mobile device with own data : Add

Step 2: Add  SIP credentials  and change Displayname to TBR22_EN300494. The value "TBR22_EN300494"for the  Diplayname  is necessary to change the random PIN to "0000"

Step 3: Start the registration with Button " Start Registration" 

Pin for mobile device registration is set to "0000"