1.2 Routers  
  1.2.3 Router external connections  
The three basic types of connections on a router are LAN interfaces, WAN interfaces, and management ports. LAN interfaces allow the router to connect to the Local Area Network media. This is usually some form of Ethernet. However, it could be some other LAN technology such as Token Ring or Asynchronous Transfer Mode (ATM).

Wide Area Network connections provide connections through a service provider to a distant site or to the Internet. These may be serial connections or any number of other WAN interfaces. With some types of WAN interfaces, an external device such as a CSU is required to connect the router to the local connection of the service provider. With other types of WAN connections, the router may be directly connected to the service provider.

The function of management ports is different from the other connections. The LAN and WAN connections provide network connections through which frame packets are passed. The management port provides a text-based connection for the configuration and troubleshooting of the router. The common management interfaces are the console and auxilliary ports. These are EIA-232 asynchronous serial ports. They are connected to a communications port on a computer. The computer must run a terminal emulation program to provide a text-based session with the router. Through this session the network administrator can manage the device.

 

Web Links

Module Interface Information

http://www.cisco.com/en/US/products/ hw/routers/ps259/products_installation_guide_ chapter09186a008007e034.html#xtocid2