We are currently running CallManager 4.2 on MCS-7825s that are EOL. We purchased new upgrade licensing and new Cisco supported HP servers to run CUCM 8.6. We want to start all over and not bring any of the configuration from the old system. We would like to bring up the new environment without affecting the 4.2 system to minimize downtime. My question is, can we install 8.6 new on new hardware with upgrade licensing, and have the licensing be active? Do we have to touch the old environment at all? Do we have have to run some sort of upgrade tool on the 4.2 environment to determine phone counts. The less we touch the 4.2 environment the better as it is in a fragile state.