Mature Unified Messaging Will Use Open Standards - Technology Information - Column

Computer Technology Review,  July, 1999  by Richard M. Tarabour

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Richard Tarabour is a director in the advanced services planning and engineering department at Telcordia Technologies (Redbank, NJ).

This article is the last in a three-part series. The second part ran in the June issue of CTR.

There is more than one way to build a unified-messaging system. Each service provider's most advantageous approach will depend in part on its starting point. The major issue is whether you have existing servers you're using to provide single-medium messaging. If so, you probably need to continue using them for at least a time to recoup your investment. That simply means that you'll migrate from your current services into unified messaging, distributing the processing load among interconnected servers. A new service provider entering the messaging market for the first time might go straight to a single centralized server to support collection of all media and delivery to the recipient customers. The ideal architecture of either kind is flexible; so that either specialized or centralized servers become modules on which to build.

The argument has been made that a central server may be less reliable than multiple servers, bringing the whole service down with a single failure and providing less flexibility for handling peak usage volumes. This is really a concern only if the centralized server is one form of messaging and is now being a called on to surpass its limits for processing or number of ports. There's nothing to keep unified messaging from being deployed on fault-tolerant, high-availability, even redundant servers. If one means of access goes down such as a LAN, for example, other means such as the telephone interface will remain available.

A unified server certainly simplifies other processes, including the directory- which yields ongoing benefits in more accurate data and in easier and less-costly maintenance. The directory also facilitates effective integration with existing operations systems or those that support other services, such as service management, billing, and network management. That kind of integration is vital to realizing economies of scale and other administrative cost efficiencies. Billing integration can be especially important if you want to bill for unified messaging on the basis of usage. Once you have such a system, recording transactions and tracking user navigation, you can also use it to fine-tune the unified-messaging application and even for targeted marketing of certain features.

The greatest flexibility, no, matter how many servers you use, comes with an architecture based on network objects. Bellcore's own Unified Messaging Services Platform, for instance, has each call (or user interaction) "terminate" in as software Telecom Object. This call controller manages the signaling interface to the network and the variety of media that may need to be recognized to handle the callet's choice of aces mechanism, including DTMF (Touch Tone) signals, speech recognition, and fax modems. The Telecom Object finishes its object by binding the call with an "application object" that gathers the customer's preferences from a profile and invokes the appropriate applications to provide the specific service features that customer has ordered. It also monitors the applications for proper functioning.

The vital difference that makes unified messaging possible is of course the a matter of digitalization. It's what makes voice and email and fax all look the same, at least to the system. It's that homogeneity that lets you put them together in a single "message store." This is another point of flexibility and migration, however. If you already have some message-storage resources in place, there's no reason to discontinue their use as long as you supplement them with storage capacity for the media you haven't served before and as long as you have connecting software to integrate the various message types.

There is a trade-off between cost and efficiency in implementing your unified-messaging system. A unified messaging system. A unified message store will make for simpler and better-integrated operators process. As a platform, the unified store is more flexibility extensible to support multimedia feature enhancements such as compound messaging and video messaging.

The converging industries that are making unified messaging a reality have been acting to remove some of the biggest uncertainties about implementation. Vendors are developing technical standards on which multiple service providers and equipment manufacturers can base the key components of a rational flexible, interoperable system. Consortiums such as the Enterprise Computer Telephony Forum (BCTF), the intelligent Network Forum (INF), the Electronic Messaging Association (EMA), and the Object Management Group (OMG) are all working on interoperability standards and process, which help top open the unified messaging market.

Standards are especially important at the messaging interfaces-between one server and another, between the customer's "client" device and the server-and for system directory. Several widely accepted standards are already in place to facilitate the exchange of messages among network-service computers. For transferring email over networks that use TP, the SMTP and MIME have emerged as complementary standards, and MIME for "rich" message content such as formatted text, voice, and binary files. For voice and fax interchange over the Internet, there is the Voice Profile for Internet Mail (VPIM), created by the cross-industry EMA, which is rapidly gaining acceptance. VPIM uses SMTP messages with MIME attachments, which would allow a unified-messaging system's server to send and receive email, voice messages, and faxes, all using same components.