Writing this blog entry is a bit overdue, over the past few months I have had a few colleagues run into an issue with Cloud PBX users with AudioCodes or Polycom VVX phones (3PIP) not properly displaying the Message Waiting Indicator (MWI) for voicemail messages. NOTE: visual voicemail still works properly and the users’ voicemail get delivered to their inbox.
(Shout out to Scott Middlebrooks and Jason Sloan)

The missing MWI is a bit of a ‘head-scratcher’ since Azure Voicemail services CloudPBX users in Skype for Business Online and deposits the Voicemail in Exchange Online. But come to find out, Exchange Online Unified Messaging is actually the delivery method for MWI to the 3PIP devices.

The following needs to be properly configured to get MWI properly working on your phones in this scenario:

  • Exchange Online Unified Messaging
    • UM Dial Plan – make sure it is ‘SIP URI’
    • UM Mailbox Policy – (verify the ‘Allow message waiting indicator’ is enabled)
  • Each Cloud PBX user must be enabled for UM and assigned the appropriate UM Mailbox Policy

Once that is all is buttoned up, you will have MWI lighting up on your 3PIP phones!