MobiControl cloud instances are hosted on AWS.  Regarding your enrollment problems, you need to provide more information such as device platform(s), device mode(s), error/warning messages shown on the device/server-log, network infrastructure, etc.

If you are enrolling iOS devices on a closed Wifi network with just the firewall exceptions you listed in your post, you probably need to consult Soti support team to provide you with additional FQDN/port/protocol of various Apple's services based on the iOS EMM policies you are going to use.

Thanks for your valuable reply, confirmed cloud hosted on AWS.  Rest of things, will check with the SOTI support...

I think you are trying to enroll aedo devices with the emm-token method (afw#mobicontrol) for which internet connection to google play is needed, i guess.