2-2Figure 2-1 Diagram for a selective QinQ implementationIn this implementation, Switch A is an access device of the service provider. The users connecting to itinclude common customers (in VLAN 8 to VLAN 100), VIPs (in VLAN 101 to VLAN 200), and IPtelephone users (in VLAN 201 to VLAN 300). Packets of all these users are forwarded by Switch A tothe public network.After the selective QinQ feature and the inner-to-outer tag mapping feature are enabled on the portconnecting Switch A to these users, the port will add different outer VLAN tags to the packets accordingto their inner VLAN tags. For example, you can configure to add the tag of VLAN 1002 to the packets ofIP telephone users in VLAN 201 to VLAN 300 and forward the packets to the VoIP device, which isresponsible for processing IP telephone services.To guarantee the quality of voice packet transmission, you can configure QoS policies in the publicnetwork to reserve bandwidth for packets of VLAN 1002 and forward them preferentially.In this way, you can configure different forwarding policies for data of different type of users, thusimproving the flexibility of network management. On the other hand, network resources are well utilized,and users of the same type are also isolated by their inner VLAN tags. This helps to improve networksecurity.Selective QinQ ConfigurationSelective QinQ Configuration Task ListComplete the following tasks to configure selective QinQ:Task RemarksConfiguring Global Tag Mapping Rules forSelective QinQ RequiredEnabling the Selective QinQ Feature for a Port Optional
