Unison Server and Unison Desktop deliver a decent unified communications experience at a great price for companies looking for basic integration of communication channels at the desktop. However, due to a current lack of extensibility to mobile devices or other applications, Unison may not be a good fit for companies with more advanced UC needs.
I tested Unison 1.1, which integrates VOIP (voice over IP), instant messaging, presence, calendaring, and e-mail into a single interface for the user, delivering an experience similar to that of a merged Microsoft Office and Communicator. Unfortunately, Unison does not currently support document collaboration among users and offers limited conferencing capabilities, and the presence capabilities are severely hampered because the information is not viewable in enough places.
Without a doubt, the best part about Unison is the price. The Unison Server and Desktop software components are free-provided you accept that your users will be served advertisements. Unison representatives promise that advertisements will be appropriate for business environments (business-to-business services and products, for instance).
During my tests, I only noticed advertisements pop up when the Desktop loaded on a client machine, but I saw no ads during normal usage. However, Unison officials anticipate there will be a higher volume of ads served down the road.
There is also a pair of for-pay alternatives for those unwilling to accept advertisements. Licenses can be purchased for $50 per user per year or $36,000 per Unison Server. The former model grants companies access to further upgrades to the Server and Desktop, while the latter does not.
Installing the Unison Server was surprisingly simple, particularly compared to the complex installation I endured with Microsoft's OCS. Unison provides install packages and scripts to install all components on a single Red Hat Enterprise Linux 5 or CentOS server (beta iterations are also available for Ubuntu server), and I found installation on my CentOS 5.2-based system took less than a half hour, save for some licensing issues I encountered.
Unison Server and Desktop components must be able to communicate via HTTPS with the Unison licensing service, which is hosted on Unison's network. Without communication for the licensing server, the mail, VOIP, calendar and IM services will not start on the server, and the Desktop will only operate in offline mode.
Unison also has available for download preconfigured virtual machines that include an operating system and Unison Server software for Parallels' Virtuozzo virtual platform.
Management of the Unison system is performed via the Web-based control panel. From the control panel, administrators can populate the system's LDAP directory and manage address books for the entire organization, department level or for individual users. Unfortunately, at this time, Unison's directory will not synchronize with existing sources such as Active Directory.
From the control panel, administrators can also configure many aspects of Unison's telephony behavior. I could control inbound and outbound routes from the Unison system, assign phones, extensions and external numbers to users, and set up hunt groups and ACDs (automatic call distributors). Unison includes a TFTP server for easy centralized configuration of certain Cisco Systems phones.
Because Unison utilizes SIP (Session Initiation Protocol), I also found it fairly simple to configure third-party IP phones to register with the system, as I successfully used Polycom IP phones and CounterPath softphones with Unison.