Your network contains an on-premises Active Directory Domain Services (AD DS) domain named contoso.com. You have a Microsoft 365 subscription. You plan to implement Microsoft Teams Rooms shared room v

The Guest access settings in the Microsoft Teams admin center control whether external users can join Teams meetings as guests, not the Direct Guest Join feature for Teams Rooms devices.

The Set-CsVideoInteropServiceProvider cmdlet configures cloud video interop (CVI) providers for third-party video conferencing, which is unrelated to enabling Direct Guest Join.

Teams Rooms on Windows reads configuration settings, including Direct Guest Join, from a SkypeSettings.xml file placed in a specific local directory on the device. Because all 50 devices are joined to the on-premises AD DS domain, Group Policy can deploy this XML file to all devices simultaneously, requiring only a single policy configuration rather than touching each device individually.

The Set-CsTeamsGuestMeetingConfiguration cmdlet controls meeting capabilities for guest users within Teams meetings, not the Direct Guest Join feature on Teams Rooms hardware.