3com WX3000 Manuel D’Utilisation

 

2-1 

Selective QinQ is an enhanced application of the VLAN-VPN feature. With the selective QinQ feature, 

you can configure inner-to-outer VLAN tag mapping, according to which you can add different outer 

VLAN tags to the packets with different inner VLAN tags.  

The selective QinQ feature makes the service provider network structure more flexible. You can classify 

the terminal users on the port connecting to the access layer device according to their VLAN tags, and 

add different outer VLAN tags to these users. In the public network, you can configure QoS policies 

based on outer VLAN tags to assign different priorities to different packets, thus providing differentiated 

services. See 

 for details.  

Figure 2-1 Diagram for a selective QinQ implementation 

 

 

In this implementation, Switch A is an access device of the service provider. The users connecting to it 

include common customers (in VLAN 8 to VLAN 100), VIPs (in VLAN 101 to VLAN 200), and IP 

telephone users (in VLAN 201 to VLAN 300). Packets of all these users are forwarded by Switch A to 

the public network.  

After the selective QinQ feature and the inner-to-outer tag mapping feature are enabled on the port 

connecting Switch A to these users, the port will add different outer VLAN tags to the packets according 

to their inner VLAN tags. For example, you can configure to add the tag of VLAN 1002 to the packets of 

IP telephone users in VLAN 201 to VLAN 300 and forward the packets to the VoIP device, which is 

responsible for processing IP telephone services.  

To guarantee the quality of voice packet transmission, you can configure QoS policies in the public 

network to reserve bandwidth for packets of VLAN 1002 and forward them preferentially.