|  |  | Overview
Now that you have a firm understanding of the OSI reference model, LANs, and IP addressing, you are ready to learn about and use the Cisco Internetwork Operating System (IOS). However, before using the IOS, it is important to have firm grasp of WAN and router basics. Therefore, in this chapter, you will learn about WAN devices, technologies, and standards. In addition, you will learn about the function of a router in a WAN. Lastly, you will perform lab activities related to a router lab setup and configuration.