Recent DrayTek routers are compliant with QinQ by extending VLAN tag option to Customer tag and Service Tag. Customer Tag is what we have always supported, and Service Tag is for the ISP to identify traffic from different customers. On the router, Customer Tag and Service tag works differently when you are using Multi-PVC/VLAN configuration for triple-play services, such as IPTV, at the same time.
Also known as the inner tag, it will be added only to the primary channel, and not affects the other channels set up at Multi-PVC/VLAN.
Also know as the outer tag, it will be added to the primary channel as well as the other channels set up on the same interface. Service Tag is the option when the ISP provides triple-play services by QinQ packets.
1) When you need VLAN tag only for Internet access, either Customer Tag or Service Tag will work.
2) When the triple-play service runs on the standard 802.1Q protocol, use Customer Tag for Internet access (data), and use the VLAN configuration in WAN >> Multi-PVC/VLAN for triple-play services (e.g., IPTV).
3) When the ISP provides triple-play services over QinQ standard, use Service Tag for the outer tag, and use the VLAN configuration in WAN >> Multi-PVC/VLAN for triple-play services (e.g., IPTV).