If you are just performing the upgrade of an existing VCS (and you would use the same process if you were upgrading one that had previously been deployed via an OVA - so you can lab test it if you need to) there will be no issues with licences - you just need the new software release key for the version you are upgrading to - which you can get from the cisco licencing portal (Get Other Licence > TelePresence Software Release Key > enter your VCS serial number > select the release key you want (ie X8.5.2) > Check your email credentials, click the "I agree" check box and then the Submit button and the request will get processed and the release key emailed you you.
Other than that, all the VCS upgrades we've done have gone very smoothly (we've done many over the years across multiple companies on both controls and expressways as the many different versions have been released) - we've not come across any issues with the upgrade process or restarting the devices.
If you're going to do the Hardware to Virtual migration - then that's a different set of complexities and will need further planning.
Wayne
--
Please remember to rate responses and to mark your question as answered if appropriate.
Wayne
Please remember to mark helpful responses and to set your question as answered if appropriate.
