The basic configuration for AToM is pretty straightforward. You must first select the encapsulation type of the customer-facing (CE-facing) interface on the PE with the following command:
Router(config-if)# encapsulation encapsulation-type
Then you enable AToM by specifying the xconnect command on the CE-facing interface, as follows:
Router(config-if)# xconnect peer-router-id vcid encapsulation mpls
The peer-router-id is the LDP router ID of the remote PE router. The vcid is the identifier that you assign to the pseudowire. The VCID has to be unique per pair of PE routers. As soon as you configure this command on the interface—on both PE routers—the targeted LDP session is established between the two PE routers. ...