I’m trying to supervise an existing Voicemail box with a BLF button on Debian‘s asterisk 13.14.1 system.
I mostly found this  document. I added in a context a line like:
exten = *7000,hint,MWI:31@default
With “core show hints”, I can read this:
*7000@subs : MWI:31@default State:Unavailable Presence:not_set Watchers 1
My questions are:
1. Is this “exten = *7000,hint,MWI:31@default” statement correct ?
2. What does “State:Unavailable” exactly means ? To it means “Asterisk is unable to find any MWI:31@default state”.
3. Which Asterisk version introduced this MWI/BLF/hint feature ? Was it supported in 1.6, for instance ?