This series is designed to help users prepare for the Cisco Certified Network Associate examination. It covers the OSI Reference Model and uses it to explain networks and network functions. It also explains networks and data transfers, LANs and WANs, and bridges, switches, and routers. An introduction to IOS and IOS configuration is provided, and various networking topics are examined, including TCP/IP, IP addressing and routing, IPX networking, and security. This series includes two exam preparation courses, as well as a course that introduces alternative base numbering systems used in Cisco management.