BLF Notification

[Flora_Yealink]

Hi ,
Do you mean the scenario is like below,
The phone has a DSS key, the light of the DSS key will flash if the phone has a meeting or appointment ?
In this case, I would suggest you can use push xml server feature , the server send the notification to the phone that it has meeting or appointment and control the DSS key flash.
For more details, please refer to the guide.
Yealink_IP_Phones_XML_Browser_Developer's_Guide_V73.rar
Best Regards!
Flora