This course examines how distributed computing systems operate over computer networks. It introduces fundamentals of data communication, including an overview of the use of physical media to transfer bits, time division and frequency division multiplexing, encoding, modulation, bandwidth, throughput, and noise. It focuses on packet switched networks and virtual circuit networks, including a layered approach to network design and coverage of both and OSI and TCP/IP models, and internetworking with router-based architecture, IP addressing, datagram encapsulation and fragmentation, transmission via UDP and TCP, and application level protocols such as Telnet, FTP, SMTP and others. Also, provides coverage of general topics and such as routing error handling, security and encryption. Prerequisites: CIS-221 or CIS-222 and CIS-236.