Cisco Unity Connection supports centralized voice messaging through the phone system, which supports various inter-phone system networking protocols including proprietary protocols such as Avaya DCS, Nortel MCDN, or Siemens CorNet, and standards-based protocols such as QSIG or DPNSS. Note that centralized voice messaging is a function of the phone system and its inter-phone system networking, not voice mail. Unity Connection supports centralized voice messaging as long as the phone system and its inter-phone system networking are properly configured.
When discussing phone systems involved in centralized voice messaging, there are essentially two types:
Message Center PINX—The phone system hosts the voice messaging system (the phone system is directly connected to the voice messaging system).
User PINX—The phone system is remote from the voice messaging system (the phone system is not directly connected to the voice messaging system).
Centralized voice messaging provides voice messaging services to all users in a networked phone system environment. Unity Connection can be hosted on a message center PINX and provide voice messaging services to all users in an enterprise assuming the message center PINX and all user PINX phone systems are properly networked.
For a centralized voice messaging configuration to exist, a suitable inter-phone system networking protocol must exist to deliver a minimum level of feature support, such as:
Message waiting indication (MWI).
Transfer, which ensures that the correct calling/called party ID is delivered to the voice messaging system.
Divert, which ensures that the correct calling/called party ID is delivered to the voice messaging system.
Other features may be required depending on how the voice messaging system is to be used. For example, if it is also serving as an automated attendant, path-replacement is needed as this feature prevents calls from hair-pinning.
Not all phone systems can serve as a message center PINX. In this case, customers may wish to consider relocating Unity Connection to Cisco Unified Communications Manager and have Cisco Unified CM act as the message center PINX with the circuit-switched phone system now acting as the user PINX.
For information on configuring Unity Connection in a centralized voice messaging environment to be hosted on Cisco Unified CM serving as the message center PINX, see the following:
Note that if customers are deploying centralized voice messaging with Unity Connection and a circuit-switched phone system, it is up to the customer to determine whether the circuit-switched phone system can serve as a message center PINX on which Unity Connection can be hosted. If so, the customer should also confirm that there is support for the desired features, for example, MWIs, transfer, divert, and path-replacement.
Inter-cluster trunks between Cisco Unified CM clusters can be QSIG-enabled using the Annex M.1 feature, which allows Unity Connection to integrate with a single Cisco Unified CM cluster. Ports in the cluster with which Unity Connection is integrated can be dedicated to turning MWIs on and off for phones in other clusters.