I started to code a few routines to fix the MWI notice on the phones for my clients.  I was having a real hard time finding any documentation about turning that little light on without digging into a complex SIP protocol manual.

This problem seems to be fixed on the newer version of Asterisk, but not all clients are on the same versions.  I noticed on my newer install that about every 5 to 6 minutes a pass is made and the MWI indicator is set or reset as needed.  This is great for the newer installs, but what about the older stable ones that sometimes don’t get the MWI notice?

I’m finally releasing three routines that should take care of any of your MWI problems.  The three programs are to set the MWI by extension number, reset the MWI by extension number and fix all phones that have voicemail accounts (Set or Reset based on voicemail).