Understanding Q-in-Q Tunneling and VLAN Translation
Q-in-Q tunneling and VLAN translation allow service providers to create a Layer 2 Ethernet connection between two customer sites. Providers can segregate different customers’ VLAN traffic on a link (for example, if the customers use overlapping VLAN IDs) or bundle different customer VLANs into a single service VLAN. Data centers can use Q-in-Q tunneling and VLAN translation to isolate customer traffic within a single site or to enable customer traffic flows between cloud data centers in different geographic locations.
Q-in-Q tunneling adds a service VLAN tag before the customer’s 802.1Q VLAN tags. The Juniper Networks Junos operating system implementation of Q-in-Q tunneling supports the IEEE 802.1ad standard.
All of the VLANs in an implementation can be service VLANs. That is, if the total number of supported VLANs is 4090, all of them can be service