IN 1995, WHEN I WAS IN MY SECOND YEAR IN COLLEGE, I was introduced to UNIX network programming.
In C, you could create sockets to open TCP connections to servers and code the servers that
accepted these connections. I remember the excitement I felt the fi rst time I created a TCP server: I
could accept connections and receive and send messages on them.
If I wanted my server to accept many concurrent connections, the common solution was to use
threads, and soon I had created my fi rst multi-threaded TCP server.
ECE/CS 372 Introduction to Computer Networks Lecture 1: Chapter 2 Application Layer Principles of network applications, Web and HTTP, FTP, Electronic Mail, DNS, P2P file sharing, Socket programming with TCP, Socket programming with UDP, Building a Web server.
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.