Module 1. WANs and Routers. WANS. WAN operates at the physical layer and the data link layer of the OSI reference model. Provide connectivity over a large geographic area Use regional Bell companies Serial connections
Routers & PCs
Router Internal Components
RAM is used for routing table information and it holds the running configuration.
The interfaces provide LAN and WAN connectivity.
NVRAM is used to store the backup/startup configuration file.
The console port provides physical access for initial configuration.
Flash memory is used for storage of full Cisco IOS software images.
ROM is used for permanently storing startup diagnostic code.
Functions of a Router Initiated by Router Configuration Files
Academy Approach to WANs
Academy training simulates this DTE to DCE connection