A benefit of the system architecture at the user level is flexible storage capability. You can use the Avaya message store, or Microsoft Exchange, or VMware Zimbra Collaboration Server (ZCS) as your storage destination for voice mail. Or, you can implement a mixture of storage destinations and set up groups or individuals within your organization so that users can select the storage destination.
At the next level, the architecture gives you the option to install a single server or to choose the front end/back end model. You can also convert later from a single server to the front end/back end model by dedicating the machine as your storage server and adding an application server or a cluster of application servers to scale with your increasing voice traffic needs. To protect against loss of messaging service or data, you can add an additional application server to the cluster for redundancy.
At the highest level, the system architecture gives you the flexibility to centralize your application and storage servers at one location or distribute your implementation by placing application servers at branch locations. The system architecture gives you the flexibility to centralize most of your implementation while distributing some sites, where local survivability is critical.
There is no one right solution for all organizations. The flexibility of the architecture gives you a range of deployment options to fit your needs. The scalability of the architecture offers you the advantage to increase capacity by adding servers as your organization grows without changing your topology. The interoperability of the architecture ensures that you can integrate Messaging into your existing network.