Refer to the exhibit.

After some system maintenance was completed over the weekend, a customer calling from the office states they hear a fast busy when trying to access their voicemail.

Avaya support verifies local network connectivity is up and Avaya Aura® Messaging server is registering no alarms. A SIP trace displays a 404 Not Found error message.

Based on what is already working, to where can the issue potentially be isolated?