While Todd Sharp is driving down the highway between Charlotte and Atlanta, a new sales order triggers a lookup for the customer phone number and salesperson (that would be Todd) assigned to it.

The system then polls Siemens OpenScape UC (unified communications) software and checks Todd's presence status, discovering that he's working remotely and available only on his cell. OpenScape kicks off a VoIP call to Todd's cell phone and, using a text-to-speech engine, reads the sales order over the phone. It then prompts Todd to press 1 to autodial the customer. Minutes after the order arrived, Todd is thanking the customer from his car.

This example is typical of how UC - an amalgam of voice communications, email, instant messaging, and presence that may also include video, Web conferencing, and calendaring - can accelerate and enhance business processes, customer service, and mobile communications. But adoption has been slow. Todd is one of the lucky few to enjoy the benefits, mainly because he works for Engage, a UC services vendor.

"Unified communications is a very overhyped market," says Mark Straton, senior vice president of global marketing at Siemens Enterprise Networks, "and one that will probably take another two to 10 years to roll out in the enterprise."

Zeus Kerravala, a Yankee Group analyst, agrees. "The market is basically where it was two years ago," says Kerravala. "Interest in the enterprise is high, but actual deployments are low."

Why? In part because most organisations have only partly completed the transition from old TDM phone systems to VoIP, the essential ingredient of UC. Plus, ROI numbers for UC remain elusive. Benefits come in fuzzy areas like higher productivity and faster decision-making, rather than revenue and cost savings. As a result, most organisations apply UC to specific parts of the business where a severe lag in reaching certain individuals can negatively affect the business.

"We're seeing early adopters in financial services where seconds lost trying to reach someone can mean lots of money," says David Marshak, senior product manager for unified communications and collaboration at IBM Lotus Software. "We're also seeing it used in the medical field for first responders, to help them quickly find a close, available doctor with this capability and equipment, and that level of clearance."

Enter the software gorillas

Another obstacle to mainstream acceptance: Unified communications solutions have tended to originate with IP PBX vendors. Though IP-based, those systems were still largely proprietary, with software tied tightly to hardware and their own client software for UC functions, including instant messaging, VoIP calls, and audio or Web conferencing. Instead of accessing UC functions from the Outlook, Office Communicator, or Sametime clients they already knew, users had to learn a new client.

Today, however, IP telephony and UC are moving toward a more IT-centric software architecture, laying the groundwork for broader acceptance. A prime example is the software-based OpenScape solution, built from the ground up on SIP and SOA, and interoperable with a variety of third-party VoIP and instant messaging systems. But the traditional software players, including Microsoft, IBM, and Oracle, are also getting into the act.

Microsoft's upcoming Office Communications Server (OCS), which replaces Live Communications Server (LCS), actually includes several SIP-based VoIP calling features typically found in such IP PBXs as Cisco's Communications Manager, along with video and Web conferencing, telephony management tools, and speech recognition.

All of that, plus Microsoft's trademark instant messaging has been rolled in a single package accessible from Microsoft's Office Communicator client or Outlook. In OCS shops, Office users will be able to click on a person's name in any Office document and instantly obtain presence information, including whether they are on the phone, and then launch an IM, a voice call, or an audio or Web conference. OCS interoperates with mainstream IP PBXs, but on its own, it can even serve as a small office's VoIP system.

Microsoft is betting heavily that UC, including voice, will ultimately revolve around productivity software. "The movement of all communications to software is the uber-level thing that's happening," says Greg Saint James, Microsoft's senior director of UC, "and it will benefit everyone, making it much easier to integrate communications with all your other processes." And of course, Microsoft expects Active Directory to host the corporate dial plan.

Oracle's Service Delivery Platform, an extension of its fusion middleware, provides a J2EE/SOA-based platform for building and deploying multiple IP communications software services, including IP telephony, video, IMS, and presence – all of which can be integrated with standard back-end business applications.

One of the smallest players, BlueNote Networks, is also one of the most advanced in enabling IP communications as a service that a variety of applications can consume. The company's flagship SessionSuite provides tools for building IP communications Web services and integrates with Active Directory and RADIUS servers. The capability of linking these services to CRM and other business applications is what could make Todd Sharp's example a reality in many organisations.

The PBX guys go deep

On the other side of this convergence are the traditional IP PBX vendors. An increasing number, including Nortel, Mitel, and Siemens, are moving full speed ahead to build in interoperability with Microsoft LCS and OCS, IBM's Lotus Sametime IM and conferencing package, and good old Outlook.

IBM recently announced it would license portions of OpenScape to bring connectivity and a single Sametime user interface to a number of different back-end IP PBX systems. This enables voice, video, conferencing, presence, and other UC features to be accessed from the software that users already know - leveraging investments IT has already made, rather than forcing migration to Cisco, Avaya, or Mitel software.

Like Siemens, Mitel is looking to pull apart its hardware and software, allowing IT to run its PBX and UC solutions on Sun servers. Even Cisco is increasing efforts to integrate its communications solutions with those of its chief UC competitor, Microsoft, as well as IBM. "We recognise that no one vendor or developer can deliver all pieces of the unified communications puzzle," says Rick McConnell, vice president and general manager of Cisco's unified communications business unit.

Avaya is also investing heavily in supporting SOA architecture for its UC functions. Last March, the company announced its Communications Enabled Business Processes solution, which exposes an array of voice communications features as Web services.

Integration is why Fred Weber, a US road construction company and materials provider, chose a Nortel IP telephony system when it was time to upgrade its 20-year-old phone system and take advantage of UC. "We use Exchange and Live Communications Server and our staff all uses Office Communicator," says Phil Hagemann, Fred Weber's CIO. "The Nortel solution just laid right on top of what we had very neatly. We didn't have to use a new interface or deal with a large learning curve. With the competing solution we would have had to use their own messenger and presence client."

Fred Weber plans to take advantage of Nortel's unified messaging to receive voice mail and faxes in Exchange, while using presence in LCS and Office Communicator to reach users when they are in the office, in meetings, or on the road. Office Communicator will also be available on staff-issued BlackBerry smartphones, so itinerant users can take advantage of find me/follow me features to route their office calls to cell phones or other preferred devices.

Leon Erlanger is a freelance author and consultant specialising in security .