Core Issue
Cisco CallManager Express, the software that controls the telephony functions, resides on a router, which accepts incoming and outgoing calls to your network. It contains a call agent, which decides where an incoming or outgoing call should be sent. It also has a database of information that contains the telephone hardware identifications, extension numbers associated with the telephones, users on the system, logins, routing destinations, call handling features and other system wide parameters.
Cisco Unity Express is an application that is enhanced by providing the voice messaging and automated attendant capabilities. The Cisco Unity Express module contains the voice mail and auto attendant software.
During the system installation process, the installer inserts this module into the Cisco CallManager Express router. A Cisco Unity Express database contains information about the voice mailboxes, auto attendant prompts and voice messages. The Cisco Unity Express and Cisco CallManager Express databases are synchronized to ensure that calls are handled correctly and voice messages are received and stored properly.
The integrated Cisco Unity Express and Cisco CallManager Express administration software allows you to configure the voice mail and auto attendant parameters and some of the Cisco CallManager Express parameters, such as extensions and telephones. As you go through the initialization and configuration procedures, be sure to save your data so that both databases have current information.
Resolution
For Cisco Unity Express, WAN H.323 calls must be converted to Session Initiation Protocol (SIP). To enable H.323-to-SIP conversion, issue the allow-connections command. A dial peer and translation rule are also required.
In addition to the dial peer created in the Configuring Dial Peers for Cisco CallManager Express Phones to Call Cisco Unity Express Voice Mail section for the voice mail extension number, a dial peer is required for incoming calls to your voice mail's E.164 number (for example, 4085552000). A translation rule must be created to convert the E.164 call to the voice mail pilot number (for example, 2000) so the call can be sent to voice mail.
For more information, refer to these documents:
