Qinq; Fig. 8.3 Example Of Qinq Configuration; Fig. 8.4 Qinq Frame - SMC Networks 7824M/VSW - annexe 1 Manual

Management Guide
TigerAccess™ EE
8.1.9
SMC7824M/VSW

QinQ

QinQ or Double Tagging is one way for tunneling between several networks.
Customer A
VLAN 200
T U
Tunnel Port
Tunnel Port
T U
VLAN 201
T: Tagged
Customer B
U: Untagged
Fig. 8.3 Example of QinQ Configuration
If QinQ is configured on the switch, it transmits packets adding another Tag to original Tag.
Customer A group and customer B group can guarantee security because telecommuni-
cation is done between each VLANs at Double Tagging part.
Double tagging is implemented with another VLAN tag in Ethernet frame header.
Preamble Destination
Preamble Destination
TPID 8100/9100 Priority
Fig. 8.4 QinQ Frame
Port which connected with Service Provider is Uplink port (internal), and which connected
with customer is Access port (external).
Tunnel Port
By tunnel port we mean a LAN port that is configured to offer 802.1Q-tunneling support. A
tunnel port is always connected to the end customer, and the input traffic to a tunnel port
is always 802.1Q tagged traffic.
VLAN 641
T T
Trunk Port
Source 802.1Q VLAN Tag
TPID 8100 Priority Canonical
VLAN Ethernet Frame
Source VLAN Tag 802.1Q VLAN Tag
Canonical 12-bit identifier
Ethernet Frame using 802.1Q Tunneling
PVID 641
T T
Trunk Port
Type/Length LLC Data
12-bit identifier
Type/Length
TPID 8100 Priority
CLI
Customer A
VLAN 200
U
T
Tunnel Port
Tunnel Port
U T
VLAN 201
Customer B
FCS
LLC Data FCS
Canonical 12-bit identifier
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