To connect a mobile device to an iOS MDM Server by installing an iOS MDM profile on that mobile device, the administrator must perform the following actions:
The mobile device connects to the iOS MDM Server.
Due to a stricter security policy introduced by Apple, you have to set up TLS 1.1 and TLS 1.2 protocol versions when connecting a mobile device running iOS 11 to an Administration Server that has integration with Public Key Infrastructure (PKI) enabled.