I have 520 series router with CME and CUE built in it and configured one SCCP phone (CP7945) and two SIP phones (Linksys SPA 922 and CP7975).
Phones registered and are working fine. Voicemail is also configured on all of them and you can leave and listen the messages on all of them.
They all have MWI configured but on CP7975 (Cisco SIP phone, firmware SIP75.8-4-1SR1S) MWI is not working, it doesn't indicate that you have new message. When you call pilot number you can listen to the message.
Both SIP phones are configured the same way.
I also tried with the CP7911 and with firmwares SIP11.8-4-1SR1S, SIP11.8-2-1S and SIP11.8-3-1S and every time result is the same - it doesn't work.
To verify MWI settings, perform the following command
show sip-ua mwi
Use this command to display SIP MWI settings from the voice-mail server. The command displays endpoint status as OFF if a message is deleted or if no message is waiting. The endpoint status changes to ON when a message is waiting.
For the configuration for the SIP MWI features following guide may help you :
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.