Aging voicemail systems, increasing interest in IP telephony, and a surge in the mobile workforce are driving companies to consider unified messaging -- a technology that has long fallen short of industry expectations.Aging voice mail systems, increasing interest in IP telephony and a surge in the mobile workforce are driving companies to consider unified messaging - a technology that has fallen short of expectations for a long time.Unified messaging products are designed to streamline the way users manage their phone, fax and e-mail messages. With unified messaging, users can open, sort and archive voice mail messages from their e-mail interfaces, for example, or listen to e-mail messages from telephones.Products have been available for more than a decade, but adoption of unified messaging technology has been slow. That's starting to change, particularly as more employees spend more time working away from the office, either on the road or from home.Companies are looking for tools to make the mobile population more productive, says Brad Herrington, product marketing manager at Interactive Intelligence. "There are a lot of things people can do with a BlackBerry or Pocket PC. They can get their e-mail and chat. But they still have to call in somewhere to retrieve their voice mails."With unified messaging, a user can be alerted when a new voice mail message is left on a company extension, then access the message in WAV file format and play it on a handheld device, Herrington says.In the past, it was tough to justify a unified messaging rollout based solely on the convenience of such features. But as corporate voice mail systems reach retirement age, companies have the rationale they need to consider unified messaging-enabled replacements.Cost justificationMany corporate voice mail systems are getting old, and vendors are announcing plans to cease development and stop providing support for a lot of legacy gear, says Krithi Rao, a research analyst at Frost & Sullivan. First-generation voice mail systems from vendors such as Octel, Centigram and Digital Sound are dead or on their last legs.As replacement becomes unavoidable, IT buyers are considering unified messaging products from major vendors such as Avaya, Cisco and Nortel, as well as smaller specialists such as Active Voice, Adomo, AVST and Interactive Intelligence.The proof is in the numbers. After anemic growth in 2003, the market for unified messaging products is starting to take off. Vendors reported an average 12% revenue growth in 2004 - a big increase over the 4% reported in 2003 and a huge gain for a mature market, according to IDC. Last year the market grew an additional 9.9% to $362 million, and IDC expects it to increase by 9% this year.Microsoft's renewed focus on unified messaging is another indication of how hot the market is getting. The company plans to include a unified messaging component in Exchange 12, which is due out by early 2007.The right fitFor companies interested in unified messaging, an important factor to consider is architecture. Not all platforms work the same. Some store different message types in a single repository, and others provide a single access layer but use separate message stores for each message type.Companies need to evaluate the architecture carefully that makes the most sense for them, Rao says. In some cases it may be desirable from a record-keeping perspective to store related voice mail and e-mail messages together. In addition, having only one message repository to administer and manage may appeal to some companies.On the other hand, some companies view a single message store for voice mail and e-mail messages a liability. "If their e-mail goes down, they don't want their voice mail going down at the same time," Rao says.Integration, too, is no small matter. Unified messaging products often are tied to a number of existing enterprise systems. When University of California at Berkeley went live with Interactive Intelligence's Communite software last fall, it integrated the system to its e-mail systems, Centrex and Nortel PBX gear, iPlanet Lightweight Directory Access Protocol (LDAP) directory and Kerberos security system.For companies wanting an all-in-one package, there are unified messaging vendors that will bundle items such as a directory server, storage and security functions with the messaging features to create a stand-alone system. But UC Berkeley wanted to make use of its existing systems, including the campus LDAP directory and storage-area network (), says Terri Kouba, a systems developer at the university. This made the implementation more complex, but ongoing management easier. "In my unit, which is communication and network services, we can have the expertise in the ISDN piece of it and the voice network, but we don't have to know LDAP, and we don't have to have a SAN expert. We can utilize the expertise that already exists on campus," Kouba says.Companies also should consider their long-term plans for IP telephony when choosing a unified messaging platform, experts say. IP isn't a prerequisite for unified messaging - companies can deploy a unified messaging suite alongside a conventional TDM phone switch, which UC Berkeley did.But IP and technologies are forcing companies to reconsider their infrastructure, Rao says. As they do so, it makes sense to consider voice mail replacements that offer unified messaging capabilities and can take advantage of interactivity among phone, e-mail and instant messaging applications.Lately vendors have been tweaking their unified messaging products to minimize disruptions during rollouts.For example, by incorporating commands that are familiar to users, such as "delete," "move" and "forward" for managing voice mail messages via an e-mail interface, vendors can lessen the user training requirement. "Users are able to use the same controls, same interface, same commands. Everything they do with e-mail they can now do with voice messages as well," Rao says.It's important to evaluate what level of access to give to each user, Rao says. Not every employee needs all the features available in a unified messaging platform, and companies can save money by judiciously doling out access to employee segments.