Overview

802.1Q-in-802.1Q (QinQ) is a flexible, easy-to-implement Layer 2 VPN technology based on IEEE 802.1Q. QinQ enables the edge device on a service provider network to insert an outer VLAN tag in the Ethernet frames from customer networks, so that the Ethernet frames travel across the service provider network (public network) with double VLAN tags. QinQ enables a service provider to use a single SVLAN to serve customers who have multiple CVLANs.