With an increasing number of devices tied to one building automation system, there arose a significant need for a highly secure communication protocol. BACnet Secure Connect (BACnet/SC) is the solution to meet this requirement. An encrypted form of BACnet communication, this protocol uses TLS encryption to ensure the integrity and safety of its communications. It introduced new secure data link layer based on the most common features that comply with IT infrastructure requirements. It has backward-compatibility with existing BACnet systems.