While configuring Call Survivability in Cisco Unified Communications Manager, what step is
mandatory to reach remote sites while in SRST mode?

A.
Enable Cisco Remote Site Reachability.

B.
Configure CFUR.

C.
Enable the SRST checkbox in the MGCP gateway.

D.
Configure the H.323 gateway for SRST in Cisco Unified Communications Manager.

E.
Enable the Failover Service parameter.

Explanation:
Call Forward Unregistered (CFUR) functionality provides the automated rerouting of calls through
the PSTN when an endpoint is considered unregistered due to a remote WAN link failure
Link: http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/srnd/8x/models.html