As you may know, UCCX 8.0 is the latest version of the Cisco Contact Center Express software out on the market, and in the past month we have seen a lot of our customer to upgrade their old systems to this new version, not only because some of the older versions will be out of support early next year but also because of the great new features available on this new version.
One of the big changes in the 8.x version is the licensing model, as it changed from a non node locked license to a node locked license schema. In the old versions of UCCX the license was not dependant on the hardware of software configuration, so basically you were able to use any license on any server without any issue. But in this new version the license gets associated to something we call now 'License MAC', which is a 12 digit HEX value created by hashing a great deal of parameters that you configure on the server, including: Time zone, NTP Server 1 (or ‘none’), NIC speed (or ‘auto’),
Hostname, IP Address, IP Mask, Gateway Address, Primary DNS, SMTP Server (or ‘none’), Certificate Information (Organization, Unit, Location, State, Country), etc. If there’s a change on any of these parameters, the License MAC also changes and you will need to request a re-host license to the Cisco licensing team in no more than 30 days.
There are two different ways to get the 'License MAC’.
First, there is the “Cisco Unified Communications Answer File Generator” to get the information prior the installation so you can request the license to Cisco as soon as you decide to upgrade your system.
To access the “Cisco Unified Communications Answer File Generator”, go to 
Walter J. Solano Vindas