When the backbone network is the L2VPN that is built based on VPLS, you can configure VPLS-based Layer 2 protocol tunneling so that protocol packets from different user networks can be transmitted on the backbone network.
Before configuring VPLS-based Layer 2 protocol tunneling, deploy VPLS-based L2VPN on PEs and the backbone network. For details, see VPLS Configuration in S2720, S5700, and S6700 V200R019C10 Configuration Guide - VPN.