In an article written for Windows NT magazine, the authors explored the question, "What is required of an ideal unified messaging system and architecture?"

Read on to find out what they learned, and how Unified Messenger satisfies the key requirements of IT professionals.

Key Need: Replication User directory entries and changes will automatically replicate to networked and remote messaging servers. Messaging objects (voice, email, etc.) will replicate based on site-by-site messaging server profiles.

Unified Messenger features a single point of administration. All administrative changes are written into the directory of the specified Exchange Server and replicated as necessary. Because Unified Messenger is distributed, it is easy to move users from one server to another. As employees move or as needs change, changes to the Exchange Server directory will automatically be replicated to all system directories, so the change is made only once.

Key Need: Centralized Management Tools Monitor and manage all mailboxes using a single graphical user interface (GUI). Add or delete subscribers easily. Move subscribers from one domain or messaging server to another easily. In an implementation of Unified Messenger, the Exchange Server administration combines all management tools into one application. A graphical user interface makes it easy to create and configure mailboxes—simply point and click.

Because Unified Messenger is distributed, it is easy to move users from one server to another. As employees move or as needs change, changes to the Exchange Server directory will automatically be replicated to all system directories.

Key Need: Single User Directory Be able to maintain a single directory entry that is used for all mailbox message types. This would allow system administrators to run only one program whenever an add, move, or delete has to be done. Typically, this directory would be maintained as part of either the email server or the LAN operating system itself.

With Unified Messenger the Exchange Server directory manages addressing for both Exchange and Unified Messenger. System managers need only make changes once—any change in one Exchange Server directory is automatically replicated to all other directories in the network.

Key Need: Integral Security System administrators will be able to set specific user rights depending on the type of message (voice, email, fax, etc.). An additional password could be required whenever faxes, for example, were transferred to an off-site fax machine. All security features are implemented as extensions of the NT's underlying security layer. Unified Messenger servers run Microsoft Windows NT, and use the ambient NT security mechanisms to protect their files and other data. Access to voice messages and e-mail through the Unified Messenger server's telephone user interface is protected by a user mailbox number and password. These are stored in an extremely secure format. In particular, passwords are never written to disk or otherwise communicated by the Unified Messenger server in anything other than an encrypted form.

The Unified Messenger administration software allows the minimum permissible password length to be set for all users in a single operation. Administrators are advised to choose lengths for their users' mailbox numbers and passwords that are commensurate with the organization's security requirements. When a user's mailbox is enabled to receive voice mail, a random numeric password is generated automatically. When a subscriber attempts to change their numeric password, the Unified Messenger software rejects any new password that would not meet the minimum length requirements or is obviously unsuitable. For example, a subscriber may not set their password to be the same as their mailbox number, nor may they choose a password that consist of a single digit, repeated n times. Access to voice messages from the e-mail client is protected in exactly the same way as access to any other e-mail messages. Configuration and monitoring of Unified Messenger servers is supported by a set of utility programs that are installed with the server. These use Windows NT security mechanisms to permit only NT domain users and groups specifically designated by the administrator to read and write Unified Messenger server data.

Key Need: Easy-to-use Graphical User Interface The unified messaging front end should require minimal training. In the case of using Microsoft Exchange, users will already be familiar with that program so training impact would be minimal. For PCs with multimedia capabilities, voice message audio can play or be recorded from a local sound card. For PCs that do not, any local phone extension or number could be specified and the unified messaging system would call that number and use the phone connection as a virtual sound card.

In an implementation of Unified Messenger, the Exchange client software resides on each user's PC. It facilitates the sending and receiving of data between the client PC and the Exchange Server, and manages the display of all messages contained in the user's Exchange mailbox. The Unified Messenger client software interacts with the Exchange client to facilitate and control the recording and playback of voice messages. The telephone is also a client for Unified Messenger. Requiring no special connections or software, any telephone is able to be used to record and listen to voice and e-mail messages. It also serves as an input device allowing the user to act on messages—replying to or forwarding messages, storing messages, or deleting them. Lucent has extensive experience in developing telephone user interfaces that enable users to gain maximum productivity from the messaging process.

Key Need: Scalable Architecture Be able to add new mailboxes, new departments, even new message servers easily and without having to tear out what already exists. Using Windows NT-based systems, multibox solutions should be "plug-in" easy.

Unified Messenger is based on the client/server architecture of Microsoft Exchange and has the capacity and intelligence to serve thousands of users with the necessary high performance and reliability. Architecture components of Unified Messenger include the Exchange Server, the Unified Messenger Server, LAN and PBX connections, personal computer clients and, if desired, gateways to outside networks. Exchange Servers and Unified Messenger Servers are standard PC systems and are modular. As an enterprise network evolves and the number of users grows, you are able to add servers as needed. There is no need to "forklift upgrade" an entire system to gain capacity or capabilities. Even better, you can add servers without taking the network down. If a problem arises with a specific server, you isolate the problem and take the server out of service while allowing the rest of the network to remain on-line.