A customer is using a SIP trunk to route calls to ITSP. To decrease the possibility of downtime, the customer invested in a failover device. How does the customer ensure reachability to ITSP, so that if one device on ITSP fails, the calls will be routed to another device?
A. Enable SIP Option Ping on the SIP profile.
B. Monitor the link using network management tools, and if it fails, manually change the routing to another working device.
C. Enable ANAT on the SIP profile.
D. Enable transmit security status on the SIP security profile.
