backup exec update from 21.2 to 22.1

we are planning to upgrade the CASO envrioment to 22; the upgrade process states to ensure latest feature pack is installed; does that mean we first have to update the CASO envrioment to latest MR for 21 and then do the upgrade to 22.

Also is the process similar, you disable comms between  CAS server and member server; install patches first on cas server  and then on other member servers?