1. ALWAYS create a backup of your configuration and data before a firmware upgrade.
2. After upgrading to 1.0.20.x, if you downgrade to 1.0.19.x and issues are encountered after downgrading, factory reset the UCM and restore the backup.
3. For UCM6xxx on 1.0.19.x, please upgrade to 1.0.20.x directly.
4. For UCM6xxx on firmware earlier than 1.0.20.x, please upgrade to 18.104.22.168 first, then upgrade to 1.0.20.x. To upgrade to 22.214.171.124, please check 126.96.36.199 release note “Important Upgrading Note” section and follow the instructions.
5. It is recommended to upgrade UCM to latest firmware for product lifespan and security improvements.