In the data dictionary, under the table numplan, there is a column called "ismessagewaitingon" I assumed that this was the MWI status of a DN. Yet querying against my system shows that I seem to always get "false" even when the phone is clearly displaying MWI. Also, setting this field to TRUE doesn't switch on MWI.
 
Am I misunderstanding this "ismessagewaitingon" field ? Is there another place I should look for MWI status ?

Thanks,
 
GTG