Network Dictionary – cVLAN and sVLAN

Another type of overlay networking is QinQ tunnelling.

QinQ involves use multiple VLAN tags in an Ethernet header so that one VLAN ID can carry another 4096 VLAN IDs in a second tag. This makes a simple and useful tunnelling strategy.

The inner tag is the one set by the customer, and the outer tag would be set by the network. It’s common in the Service Provider industry1 to refer to these as Customer VLAN and Service VLAN