Unified Messaging (UM) is one of those perennial “this is the year” technologies, always touted to be on the brink of a breakthrough. Is this truly the year for bringing voice mail and faxes into your mailbox? In this article and a couple of follow-up articles, I will review the unified messaging and unified communications landscape, take a look at the components of a typical UM architecture, talk about the potential benefits and risks of implementing UM and unified communications (UC), and discuss some of the real-world products that are available today.

Unified messaging and unified communications
I recently noticed a new addition to my Yahoo Mail account. Next to the familiar Check Mail link, there’s a Check Voice link as well. Users of Yahoo Mail can now direct their friends and business associates to a Yahoo-supplied phone number and then retrieve those messages via the familiar Yahoo Mail interface. Other services, such as onebox.com and ThinkLink, also provide consolidated fax, voice mail, and e-mail. These are great examples of unified messaging for the consumer market.

Of course, unified messaging holds even greater promise for the corporate world, where the hope is that it can help consolidate infrastructures and increase communications efficiency. UM is usually defined as the consolidation of fax, voice, and e-mail messages into one inbox, along with the ability to access those messages via a phone or the Web from anywhere.

UC applications are emerging that offer more sophisticated messaging functions, such as “find-me, follow-me” universal phone numbers and “distinctive routing” answering services that route calls differently, sending some calls to your voice mail and others to your wireless, depending on criteria you select. Using these applications, you can now direct the bill collector to voice mail, the boss to the mobile phone, and the fax to the fax machine in Hong Kong (where you’re working this week) automatically.

Basically, when implemented together, UC incorporates UM and provides additional capabilities, such as outbound dialing from the mailbox, follow-me services, text-to-speech, pager notification, and “rich mail” capabilities, like video-to-the-mailbox. Telephone carriers and network companies alike recognize the potential in these services. BellSouth and Genuity have invested heavily in consumer-targeted UM offerings, and Cisco, through its $170 million acquisition of Amteva Technologies, has made a big bet on this market as well.

Understanding convergence
It’s important to view the UM/UC market in the context of voice/data convergence. Because H.323, SIP, and other voice-handling protocols have been accepted as working standards, data traveling over the Public Switched Telephone Network (PSTN) can now be packetized and handed back and forth between data and voice networks. As IT professionals, we’re now at a disadvantage if we don’t have a basic understanding of “the voice side,” as IT folks refer to it. In my experience working on voice/data convergence projects, I’ve needed a strong grasp of telecommunications concepts, such as POP interconnection, SS7 signaling, ANI and DNIS routing, and PSTN call flows, to understand the design requirements. Whatever the fate of UC, convergence is here to stay, and IT pros need to enhance their telephony skills in order to keep up with the profession and continue delivering quality services.

As I mentioned, UM consolidates voice, fax, and e-mail and enables subscribers to handle messages from any device, whether it’s a landline phone, wireless, or Internet PC. The ability for busy people to consolidate their messages, access them remotely, and handle them more efficiently seems attractive. So attractive, in fact, that analysts have predicted big things; Ovum Research forecasts a $2.2 billion UM market by 2002, and Gartner stated that 40 percent of messages will end up in unified mailboxes by then. (TechRepublic is an independent subsidiary of Gartner.)

This drive to voice/data convergence, and its potential to rock both the telecom and networking world, is at the center of the momentum behind UM. Stuart Wells, senior vice president at iPlanet, a leading vendor of IP messaging products, said, “The potential of unified messaging is not about the 150 million PC users connected to the Internet. It is about the 3 billion phone users and the 800 million cell phone users who will utilize unified messaging to gain access to a whole set of services.” Moving beyond UM to UC creates a new world of possibilities, according to Roger Walton, researcher at Ovum.

“Sending and receiving messages is just one of the things people will want to do as part of their communications activities,” Walton recently stated. “Call management, information and transaction activities, and e-commerce functions will run off the same interface. We have been working on the concept of the ‘personal portal,’ the individual’s gateway to the information world,” he continued. “Unified messaging is obviously at the core of that concept.”

How to implement it
For enterprises looking to add UC capabilities, there are two market options: Build it or outsource it. For those who want to build and own this capability, there are plenty of alternatives. Traditional telephone equipment manufacturers like Lucent, Nortel, and Siemens have rushed into this marketplace, delivering UC applications that users can integrate into their existing telephone closets or data centers.

New-world networking companies like OpenWave (the merged Software.com and Phone.com), Cisco, and 3Com have software solutions that are “enterprise grade,” designed to be deployed by the customer. Even Microsoft and Lotus are touting the rich mailbox capabilities of their new releases of Exchange and Notes.

For many organizations, outsourcing is a better choice, and there are myriad potential partners, including MessageClick, onebox.com, IBasis, and ThinkLink, that are focused on becoming communication service providers, offering UC services in an “apps-on-tap” model that marries the PSTN and the Internet. We’ll look at these offerings in greater depth and develop some decision criteria later in this series.

The building blocks
What does the architecture of a unified communications system look like? A UC architecture typically consists of the following:

  • A database
  • A message store
  • A series of gatekeepers and gateservers for access to the Public Switched Telephone Network
  • Servers to run the unified communications software
  • Additional options, such as text-to-speech servers and pager notification servers

The database acts as the user profile directory, where the subscriber can store his or her special call routing and handling preferences, and is accessed by both the e-mail system that acts as the message store and the unified communications software. In some cases, the UC software and the e-mail software each needs its own database, and then LDAP connectors are developed to integrate these directories.

The message store is typically an IP-based e-mail package. For carriers and service providers, this is usually a carrier grade e-mail system such as iPlanet Messaging Server or OpenWave Systems’ Intermail, while for enterprises, it could be Exchange or Notes. The developers of these products recognize the potential in the UC marketplace and are all rushing to deliver the most “UC-ready” mailboxes.

The gatekeepers and gateservers support voice/data convergence by utilizing H.323 and SIP protocols to convert standard voice traffic to IP packets, which can then be routed to the unified messaging application and message store. Advanced UC services like click-to-dial or variable message routing require access to telephone call control information known as SS7, which can add another layer of complexity to the infrastructure, requiring SS7 services or hardware.

The unified messaging software typically requires its own server farm, and these apps are often very resource hungry, needing many servers to handle a relatively small number of concurrent connections. The Cisco uOne (release 4.1) application, for instance, can only run about 20 “threads,” or concurrent user sessions, per server.

UM architectures can be relatively simple, leveraging an enterprise-level messaging system like Exchange or Lotus Domino, or they can be hugely complex, as in a carrier or service provider environment. I worked with a client that was preparing to offer UM on a wholesale basis and was planning a UM system that could support 1 million subscribers. The architecture we specified for this venture included 100 UM application servers, four database servers, 50 text-to-speech servers, four redundant 9-terabyte disk cabinets, plus SS7 hardware, IMAP and POP servers, queuing and caching servers, Webmail, notification and messaging servers, as well as the firewalls, routers, switches, and the network management resources required to create a secure and robust environment.

Bringing it together
The convergence of the telephone and data networks is inevitable. The economies of IP-based voice transmission guarantee it. The additional functionality, such as unified communications, which become available when you can manipulate voice messages like data, are an added incentive to migration. As convergence becomes a reality, more enterprises will move to deliver these services, and more IT pros will be supporting UC environments. We’ll look at some real-world products and consider issues associated with UM/UC implementation in my next article.
We look forward to getting your input and hearing about your experiences regarding this topic. Join the discussion below or send the editor an e-mail.