Explanation/Reference:
Use display l2vpn pw to display PW information.
service-instance is one customer service being served on the port, you can consider the number behind
"service-instance" command as local identifier on the port, it doesn't have to match on the other side.
Example configuration:

Syntax Explanation:
service-instance is one customer service being served on the port, you can consider the number

behind "service-instance" command as local identifier on the port, it doesn't have to match on the other side.
encapsulation s-vid 10, this command specifies which vlan tagged traffic is to be taken and transported

to the other side of this L2 tunnel.
xconnect peer 4.3.2.1 pw-id 1222 is telling the router to what remote LDP peer the L2 VLL should go to

and a unique pw-id (PseudoWire ID) that has to match on both ends and is unique identifier of the tunnel.
Note: A pseudowire (or pseudo-wire) is an emulation of a point-to-point connection over a packet-switching network (PSN).
References: http://networkgeekstuff.com/networking/l2-mpls-vllsvpls-overview-including-martinikompella- mode-h3c-configuration-examples/