Which statement describes a disadvantage of using the Cisco TFTP service to serve IP phone load files? 

Answer options:

A. The Cisco TFTP services can run on only one Cisco Unified Communications Manager server in a cluster.
B. Because TFTP operates on top of UDP, there is a high risk of corrupted load file delivery at the completion of the TFTP process due to undetected data loss in the network.
C. If a response is not received in the timeout period, the TFTP server will not resend the data packet.
D. Packet loss can significantly increase the TFTP session completion time.
E. Because TFTP operates with an adaptive timeout period, the time to complete the file transfer is unpredictable.

D

Voice traffic cannot recapture lost packets. Rather than retransmitting a lost network connection, the phone resets and attempts to reconnect its network connection. References: http://www.cisco.com/en/US/docs/voice_ip_comm/cuipph/6921_6941_6961/7_1_2/english/admin/guide/6921trb.html#wp1031181