1.3.1 Configuration Information:
On PE1:
#
Vsi test static
  Pwsignal ldp
   Vsi-id 1
   Peer 111.111.111.111
#
On PE2:
#
Vsi test static
  Pwsignal ldp
   Vsi-id 1
   Peer 90.90.90.90
#

1.3.2 Packets into the Tunnel:
1. If the packet sent by CE1 carries a VLAN:
 
When a packet enters a tunnel from PE1, the VLAN is brought to the peer PE2:
 
2. If the packet sent by CE1 carries two VLANs:
 
When PE1 enters the tunnel, both VLANs are brought to the peer PE2:
 
3. If the packet sent by CE1 carries no VLAN, the packet is directly encapsulated in the original packet based on the original packet and then forwarded to PE2.

1.3.3 packets out of the tunnel:
When a packet comes out of a tunnel, regardless of whether the packet received from the peer PE carries the VLAN information of the original packet, each version does not process it. The MPLS header is stripped off and then transparently transmitted. The local CE, that is, the value of the VLAN carried in the original packet received by PE1 and sent by PE2 is forwarded to CE2.
 
1.3.4 Supplementary explanation:

For applications where VSI is bound to VLANIF, no matter how the corresponding physical port is added to the VLAN, the packets on the CE side must all have the same VLAN. Otherwise, the packets cannot be forwarded by VPLS and will be discarded. And each version has this requirement.

The summary of  Handling of VLANs in Packets in Various Versions of L2VPN Configurations .http://forum.huawei.com/enterprise/en/forum.php?mod=viewthread&tid=453137