How to setup WAN at home

LAN and WAN are similar layer 1 and layer 2 technology. Small company usually use a leased line to connect the LANs in their branch offices cross a WAN.

Knowing the following 3 factors, you should be able to setup a WAN lab at home.

1. The leased line service conceptually acts as a full-duplex crossover Ethernet link between two routers. 
2. Another factor about WAN is you need a CSU/DSU device. A CSU/DSU is a digital signal processing device. The DSU portion is responsible for timing, and actually connects to the DTE router via its serial port. The CSU portion is responsible for terminating the service provider’s link, and handles transmitting and receiving data from the DCE switch over the WAN link.
3. The DCE cable has a female connector, while the DTE cable has a male connector. You can plug the DTE cable directly into the DCE cable, skipping the CSU/DSU device. As a result, the WAN link is conceptually two routers linked by a cross over cable.

Follow the following guidelines, you should be able to figure out how to setup the network:

• You need to get these equipment from your friends, cisco, ebay, craggiest, amazon etc: one DCE/DTE DB60 Crossover Cable, two cisco routers with WIC-2T interface.
• Now you can plug one side of the crossover cable into one cisco router's  DB-60 port. This router will acts as the service provider's DCE switch; you then plug the other end of the crossover cable into another cisco router's DB-60 port. This router will act as the organization's DTE router. 
• The only problem at this point is, you don't have DSU to provide timing. Don't worry, you can configure serial clocking using the "clock rate 128000" command on the router that act as the DCE switch. The rest of the configuration is the same as connecting two routers with serial connection.

R1(config-if) # interface S0/0/1

R1(config-if) # ip address 172.16.3.1 255.255.255.0

R1(config-if) # clock rate 128000

R1(config-if) # no shutdown