How does PBB forward broadcast, unknown-unicast and multicast traffic from a B-VPLS to an l-VPLS?

The receiving PE checks the l-TAG in the l-SID to determine if there is a local l-VPLS on the node.

The receiving PE checks the l-SID in the l-TAG to determine if there is a local l-VPLS on the node.

The receiving PE checks the service label in the mpls header to determine if there is a local l-VPLS on the node.

The receiving PE checks the multicast B-DA to see if an l-SID has been mapped to the B-DA that matches a local l-VPLS on the node.