Layered network architectures; overview of Transmission Control Protocol (TCP)/Internet Protocol (IP) suite and introduction to sockets. Packet switching based on datagram and virtual circuit switching. Logical link control: Retransmission strategies, framing and error control. Medium access control and local-area networks (LAN). LAN interconnection with bridges. Introduction to the control plane of the Internet, routing algorithms, and routing protocols (e.g., Open Shortest Path First (OSPF) and Border Gateway Protocol (BGP)). Transport protocols used on the Internet (e.g., Transmission Control Protocol (TCP) and User Datagram Protocol (UDP)). Application-layer protocols (e.g., Domain Name System (DNS) and Hypertext Transfer Protocol (HTTP)). Elements of network security, security mechanisms on the Internet, known attacks and countermeasures.