Refer to the exhibit. After system maintenance is performed, users report that when they press the
messages button on their IP phones, they hear nothing instead of the opening voicemail greeting.
The IP phone displays “Ring Out”, but nothing else happens. What is the cause of this problem?

A.
FastEthernet0/1 is shut down

B.
Not enoughephones to support voice mail.

C.
IP source address is invalid

D.
SIPdial peer is missing

E.
IP route statement is incorrect.

Explanation: