The BACnet protocol currently uses the connectionless User Datagram Protocol (UDP) for both Annex H and BACnet/IP communications. However, it is possible that Trans- mission Control Protocol (TCP) transport will be utilized for some service in the future, and so threats specific to TCP have been included. Even if TCP/IP is never used as part of the BACnet protocol, it still can be used to gain access to the building control system web servers, get access through the corporate firewall, and be used for denial of service attacks on the external network on which the BCS may depend. The class.
