Hi Michael,
The licenses are aquired after the Upgrade has been completed without the PAK Registration (unlike CCM 6.x). Here is the method;
Upgrading Product Licenses
When you upgrade from supported Cisco Unified CallManager Manager 4.x releases, the system calculates the licenses that are required for existing devices and Cisco Unified CallManager nodes and generates an intermediate file (XML file) that contains this information. You use this file to obtain license files that you can upgrade into Cisco Unified CallManager Administration. You receive these licenses free of cost because you are already using these phones for a Cisco Unified CallManager 4.x release.
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Note You need to upgrade product licenses only if you upgrade from a 4.x release to the 5.1(3) release. You do not need to upgrade licenses if you upgrade from a 5.x release to release 5.1(3).
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Use the following procedure to obtain licenses for Cisco Unified CallManager when upgrading from supported 4.x releases.
Procedure
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Step 1 After you complete the Cisco Unified CallManager upgrade process, navigate to Cisco Unified CallManager Administration and choose System > Licensing > License File Upload.
The License File Upload window displays.
Step 2 Choose the license XML file from the Existing Files drop-down list, and click View File. A pop-up window displays that has the license information for existing devices and nodes. Copy this information. To copy the contents on this window, you can use Ctrl-A (Select All) and Ctrl-C (Copy).
Step 3 Navigate to the License Registration web tool at https://tools.cisco.com/SWIFT/Licensing/PrivateRegistrationServlet?FormId=806.
Step 4 Enter the MAC address of the Ethernet 0 NIC of the first node of the Cisco Unified CallManager cluster.
Step 5 In the text box that is provided, paste the license file contents that you copied in Step 2 by using the appropriate keyboard shortcuts, such as Ctrl-V.
Step 6 Enter a valid e-mail address and click Continue. A license file generates.
The system sends the license file to you via E-mail using the E-mail address that you provided.
Step 7 You must upload the license file to the server with the matching MAC address that you provided in Step 4. See the "Upgrading Product Licenses" section.
Step 8 You can obtain licenses for new devices that you are adding to the upgraded system, if your system requires additional device license units. For more information, refer to the document Installing Cisco Unified CallManager.
http://www.cisco.com/en/US/docs/voice_ip_comm/cucm/upgrade/5_1/upgrd513.html#wp38697
Hope this helps!
Rob
