Installing the Central Controller on a Separate Server
Our recommendation is to install the Callisto central Controller on your ConfigMgr site server. The reasoning for this is that the site server will already have high speed access and the required permissions to the ConfigMgr SQL Database, so no additional configuration will be required. It is fully supported to install the Central Controller on separate server however, and here's what's required. Windows Server 2012R2 or later Internet Information Services CORS, and the DotNet components referenced in the Installing the Central Controller article. You will install the Controller in the same way as in the article above. Once installed the Controller needs Datareader access to the ConfigMgr SQL Database. By default the identity the App Pool is installed with is Local System, so you can continue with this and grant the Computer Account datareader, or you can manually modify the App Pool identity to a service account and grant that account rights to SQL. We discuss assigning rights and changing the AppPool identity in this article Assigning Database Permissions - Callisto (getcallisto.io). Once you've granted the relevant permissions and have the Controller installed you should be good to go. You can return to the Welcome experience and provide the connection details for the Controller website and port. You can also modify these later in the Administration page of Callisto: