I am facing the unusual issue. One of the cisco 6921 phone is displaying the "new voice mail" notification.
We have listened and deleted old voicemails.
Phone was factory reset. I have left new voice mail that was received and opened but the notification is still present.
Is there any way to dismiss the message on the phone? Please advise if you experienced anything similar. Thank you.
In Unity Connection, access the user's account and go to Edit > Message Waiting Indicator. Check the box for his/her number and click "Reset All". That will cause CUC to send the Off code out to the phone.
That said, this menu will also show you what CUC considers to be the correct setting (on or off).
I don't use unity for voicemail in my environment. There is exchange/skype for business with anynode connector setup that is used for voicemail. No issues with other +1000 users therefore assume it is related to desk phone. I wonder how could I acknowledge / dismiss the notification. Thank you.
MWI is controlled by the system that provide voice mail service. In your case Exchange. You would need to look at this in that system.
There should be some way to sync the MWI for the account/DN from the voicemail system. The status that CUCM has for a device - including the status of the MWI light - is stored in CUCM so that even a factory reset of the device would not turn the light off as CUCM would believe it should be on when the phone re-registers.
You would be able to test that it is not the device itself by having it register as a different phone. (Change the MAC on the existing record, then build a new phone with the device's MAC and having it register.)
I have heard that you can force this messages on/off with the sip messages. Could you advise how to approach sending those messages to the device? Thank you
For SCCP voicemail intergrations, the voicemail system will send the MWI on (or off) code followed by the DN to CUCM. That code instructs CUCM to then send the code itself in a message to the phone, thereby turning the light on or off. On the phone itself, you can type in the on/off code manually (providing the partition of the MWI on/off codes are in the CSS of the phone) to change the indicator. Unfortunately, for SIP voicemail integrations those codes don't exist as SIP uses SIP messaging to turn the indicator light on/off.
Even if your phones use SCCP it’s not very likely that the integration between CM and Exchange would use this protocols. It would very likely be a SIP integration, but I’ve never worked on this type of integration so I’m only guessing. Either way it’s the protocol used for the connection between your phone system (CM) and the voicemail system (Exchange) that would influence how you could turn on or off MWI on a phone.