Database Access Control

Cisco UC Database

The data in the CUCM database is divided into two types, as described in the sections that follow.

Static Configuration Data

Static configuration data is created as part of the configuration of the CUCM cluster. Read/write access to this data is provided for the publisher only. Subscribers provide only read-only access to this data. If the publisher becomes unavailable, the subscriber data can be used to process calls, but it cannot be modified. Database replication is unidirectional, from the publisher to the subscribers. Only CDRs and CMRs are replicated from the subscriber servers to the publisher. All other configuration information is downloaded from the publisher.

User-Facing Features

You have learned that the publisher is the only server with a read-write copy of the database, and all configuration changes should be made on the publisher. These changes are then replicated downstream to the subscribers. This model represents a single point of failure from the perspective of moves, adds, and changes (MAC). The problem is further exacerbated because the publisher was the only server in the cluster responsible for call-forwarding changes, extension mobility logins, and message-waiting indicators before CUCM 6.0.

CUCM 6.0 treats a portion of the database as dynamic configuration data. Read/write access to dynamic configuration data is provided on all servers, allowing certain information to be modified if the publisher server is unavailable. The dynamic information that can be changed during a publisher outage is known as user-facing features (UFF). UFF data is replicated from the subscriber servers where the change was initiated to all other subscriber servers in the CUCM cluster.

Examples of UFFs include the following: Cisco unified communications manager

Call Forward All (CFA)

Message Waiting Indication (MWI)

Privacy, Enable/Disable

Do Not Disturb, Enable/Disable (DND)

Extension Mobility Login (EM)

Hunt Group Login Status

Monitor (future use)

Device Mobility

CTI CAPF Status (Computer Telephony Integration, Certificate Authority Proxy Function)

The services listed in Table 1-1 rely on the availability of the publisher server regardless of the version of CUCM used.

Table 1-1 Publisher Server Required Services

Component

Function

CCMAdmin

Provisions everything

CCMUser

Provisions user settings

BAT

Provisions everything initiated by the Bulk Administration tool

TAPS

Provisions everything initiated by the Tool for Auto-Registered Phone Support

AXL

Provisions everything initiated by the AVVID XML Layer service

AXIS-SOAP

Enables and disables services through SOAP

CCM

Inserts phones (auto-registration only)

LDAP Sync

Updates end-user information

License Audit

Updates license tables