Support Services - What does the "Denying MWI subscription" error message mean
Example of one of these errors
[1443312220] NOTICE[11256] res_pjsip_mwi.c: Endpoint '888' already configured for unsolicited MWI for mailbox '888'. Denying MWI subscription to 888
When a mailbox associated with a SIP endpoint receives an MWI (Message Waiting Indicator) notification, the phone will know that there is an unread voicemail in the mailbox.
There are two main ways that an endpoint can be configured to receive the MWI notifications from the PBX.
The phone can can request to receive MWI messages. The endpoint will do so by sending a "Subscribe" message to the PBX.
The PBX can be configured to send "unsolicited" MWI notifications to the endpoint. Thus negating the need for the endpoint to subscribe.
If Asterisk is configured to send unsolicited MWI notifications to an endpoint and the endpoint sends a subscribe request, Asterisk will deny the request and record in the logs that the endpoint is already configured to receive unsolicited MWI notifications.
Thus, this error message is completely benign and can be ignored.
For more details, see the Asterisk Wiki page about MWI.