What happens if IP phone B fails over?
A. The Call Back feature is still activated. However, it can take some time (20 seconds) before Call Back Handlers are in sync. In this case, the assumption is that the IP phone fails over because, for instance, the Cisco CallManager service goes down. If, for instance, Computer Telephony Integration (CTI) or the Cisco Extended Functions (CEF) service goes down as well, the Call Back feature is lost.
