Cisco UCS C210 M2 is a server sold by Cisco for its unified computing series of products. Inside the server contains a customized firmware known as Cisco Integrated Management Controller. This CIMC is for managing server resources only, it does not contain other application components such as Voice (CUCM). At first look I thought the server come pre-installed with an OS however a CD provided with the package actually has choices of OS to be chosen: Windows, RHEL and Suse Linux, however these options are to aid OS installation, the Server Conf utility DVD actually does not contain any OS, you need to provide the OS yourself. If you are buying CUCM 8.6, the CUCM is packaged with RedHat Linux.