System Requirements for Message Broker 3.X for Windows:
Any Windows Server
RAM: minimum 1 GB allocatable
HDD: the program itself has minimal disk space requirements. What can grow big and quickly take several gigabytes are the log files. Therefore 50GB above the system requirements are recommended. Log files retention policy should be considered and implemented to keep the HDD requirements lower
Processor 2.10 GHz (recommendation for systems with exchange of up to 30000 IDOCs/day, up to 350 productive technicians with 1 job/day)
remote access: installation and administration of Message Broker requires a (remote or physical) access to the machine, with administrative rights (necessary to install/update program binaries and start/stop windows service)
Network encryption and the (lack of) maintenance of certificates and algorithms to do those can cause connectivity issues. Note that especially root certification authorities should be updated regularly. In case of connection issues to FSM Cloud due to untrusted TLS certificate please refer to the following SAP note: https://launchpad.support.sap.com/#/notes/2943007.