we would like to upgrade a 2 server cluster 4.2(3) on 7825 servers to version 7.1. As we have old, but supported 7835 servers and to smooth and ease up the upgrade, we would like to use those 7835 servers. Now we have UCSS for CUCM. Is this allowed? Or do I need to also buy a Node License upgrade to this bigger server platform?
Many thanks in advance