What service must be activated on a Subscriber to support WebAttendant?

A.
Cisco Database Layer Monitor

B.
Cisco IP Voice Media Streaming

C.
Cisco TFTP Server

D.
Cisco CDR Insert

E.
Cisco Telephony Call Dispatcher

Explanation:
Understanding the Cisco Telephony Call Dispatcher
The attendant console application registers with and receives call-dispatching services from the Cisco Telephony Call Dispatcher (TCD). The Cisco TCD, a Cisco CallManager service, provides communication among Cisco CallManager servers, attendant consoles, and the Cisco IP Phones that are used with the attendant consoles.
Note
If you use the attendant console in a cluster environment, make sure that all CiscoCallManagers within a cluster have the CiscoTCD service activated and running. You must manually activate the service through CiscoCallManager Serviceability. Attendant console redundancy requires this setup to work properly; however, not all CiscoTCDs are required to have a route point.