Which of the following statements regarding Publishers and Subscribers is valid? (Choose all that apply.)

A.
A Publisher is a Read-Write database

B.
A Subscriber is a Read-Write database

C.
A Publisher is a Read-Only database

D.
A Subscriber is a Read-Only database

E.
Both Publisher and Subscriber databases are Read-Write

F.
Both Publisher and Subscriber databases are Read-Only

Explanation:
Cisco CallManager Embedded LDAP Directory
Cisco CallManager uses the Data Connection Directory (DC-Directory) as an embedded LDAP directory. This directory stores authentication and authorization information about users and comes standard with Cisco CallManager (does not require any special configuration or installation). Authentication establishes the user right to access the system, while authorization identifies the telephony resources that a user is permitted to use, such as a specific telephone extension.
After installation, the Cisco CallManager publisher server contains the read and write version of the LDAP directory and the database, while the subscriber servers contain read-only versions. The system uses LDAP to communicate to and from Cisco CallManager and all of the supported applications and uses the TCP port 8404. Administrators access the embedded LDAP directory from the Cisco CallManager Administration User Configuration window. Administrators use the User Configuration window to add, update, and delete user information such as userid, password, and device association.
http://www.cisco.com/en/US/partner/products/sw/voicesw/ps556/products_administration_guide_chapter09186 a