Handover allows you to switch from VoIP over Wi-Fi to a cellular voice network call while on a call (Note that the other party will hear silence briefly.) While on a cellular call, tap "handin" to switch from the cellular voice network to VoIP over Wi-Fi.
The Automatic Handover allows VoIP calls over Wi-Fi to be automatically switched to your carrier's cellular voice network when the Wi-Fi connection deteriorates.
Please note that Mitel Connect instant messaging is not compatible with Skype or Microsoft Teams. Mitel Connect instant messaging requires the TeamWork for Mobile application.
For additional information please see the latest Connect for Android and Connect for iOS manuals:
Managing Settings using Connect for Android