After a Dot1q termination sub-interface is configured, you need to configure the VPN service so that users at both ends of the L3VPN can communicate with each other.
Configure L3VPN on the CE, PE, and P. For details, see BGP/MPLS IP VPN Configuration or BGP/MPLS IPv6 VPN Configuration in the S2720, S5700, and S6700 V200R019C10 Configuration Guide - VPN.