Why did the users not realize the WAN was down and prevented access to their voicemail?

Company X has a Cisco Unified Communications Manager cluster and a Cisco Unity Connection cluster at its head office and implemented SRST for its branch offices. One Monday at 2:00 pm, the WAN connection to a branch office failed and stayed down for 45 minutes. That day the help desk received several calls from the branch saying their voicemail was not working but they were able to make and receive calls.

Why did the users not realize the WAN was down and prevented access to their voicemail?
A . All the phones should have started ringing the instant the WAN connection failed to signal the start of SRST mode.
B . All calls should have dropped when the WAN failed so users would be instantly aware.
C . Although the phones were still working, the users should have noticed that the phone displays said "SRST Fallback Active".
D . The voice administrators at the head office did not call the users to notify them.

View Answer

Answer: C