The Portfolio Manager Server must be installed and started in order to use the MiFID II services. The minimum configuration for the backends is sufficient here, i.e. at least 2 standard backends. To use document management for the Postbox, you need backend servers of the type "Async/Document".
A "Service Gateway" backend is also used for communication with the services, which requires around 1 GB of additional main memory.
The "Service Gateway" backend requires more memory and CPU if several Infront Portfolio Manager users use the services at the same time.