Yealink DND Star Codes for Sonictel PBX with or without TLS

Note: There's a known issue with DND feature not holding when the phone also uses TLS when activating using the phones DND button,

To solve this, have the customer use the STAR CODES  *78 to turn ON DND and *79 to turn OFF DND

This will also sync with the phone and show the DND indicator (red circle with a dash) on the screen

DND Star Codes will work with or without TLS

*78 = DND on

*79 = DND off