Any Transport over MPLS allows the establishment of layer 2 adjacencies between geographically isolated sites.
xconnect is the command used to create a bridged connection with the specified destination. The command is broken down with the xconnect keyword followed by the peering router address and the unique virtual circuit ID (VCID). This VCID must match on both ends of the connection. The encapsulation can be L2TPv2, L2TPv3, or MPLS.
Always remember there must always be a unique address on each router in order for this to work.
Layer 2 pseudowires have two segments, Segment 1 for the customer facing port and segment 2 for the core configuration.