Yes, you can control who is allowed to use extension mobility (EM) by creating profiles and user accounts for ONLY those people you want to use EM. If other users attempt to use those phones which have EM enabled, they won't have an EM profile associated with their user account and therefore will be unable to login to the phone(s).
Yes, you can control which phones are enabled for EM (ie. which phones those people are allowed to login to) by only subscribing those phones to the EM service. EM users will not find the EM service on those phones not subscribed and will not be able to logon to those phones.
1. EM user will only be able to logon to phones subscribed to the EM service
2. Only EM users can logon to phones subscribed to the EM service.
Are you getting this error “Installer User Interface Mode Not Supported. The installer cannot run in this UI mode. To specify the interface mode, use the -i command-line option, followed by the UI mode identifier. The value UI mode identifiers...
The below trick might come handy when you have to add a new node to a cluster but you don't have or is unsure of the security password for the publisher. This procedure has been around for ages.
1) Login into the CLI of the Publisher.