I have a setup with Yealink phones & Asterisk Server (all latest patches).

I am using BLF to display the states of other phones. While this works MOST of the time (busy, being called) it does NOT work when a phone is NOT regisstered at all, the yealink phones display a green dot EVEN if a phone is turned off (try explain this to users, they are shaking their heads!!!)

I can see on the Asterisk server it shows correctly in the logs when a phone is disconnected. It also advises the otehr phones correctly when a phone is busy, even if a person starts dialing – the red dot shows up milliseconds later on ALL
of the other phones.

I have asked a question about this before Green Dot

So I went and asked Yealink about this. The reply was something like this: “Currently the phone can only support the BLF LED display with early/confirmed/terminated/proceeding NOTIFY states.”

My question now is can I implement this properly on an Asterisk server?
I.e. when a phone gets disconnected that all other phones are advised
“hey I am not available” and actually show a RED dot.

thanks