Samsung iES4028F Management Manual page 257

QinQ tunneling uses a single Service Provider VLAN (SPVLAN) for customers who
have multiple VLANs. Customer VLAN IDs are preserved and traffic from different
customers is segregated within the service provider's network even when they use
the same customer-specific VLAN IDs. QinQ tunneling expands VLAN space by
using a VLAN-in-VLAN hierarchy, preserving the customer's original tagged packets,
and adding SPVLAN tags to each frame (also called double tagging).
A port configured to support QinQ tunneling must be set to tunnel port mode. The
Service Provider VLAN (SPVLAN) ID for the specific customer must be assigned to
the QinQ tunnel access port on the edge switch where the customer traffic enters
the service provider's network. Each customer requires a separate SPVLAN, but this
VLAN supports all of the customer's internal VLANs. The QinQ tunnel uplink port
that passes traffic from the edge switch into the service provider's metro network
must also be added to this SPVLAN. The uplink port can be added to multiple
SPVLANs to carry inbound traffic for different customers onto the service provider's
network.
When a double-tagged packet enters another trunk port in an intermediate or core
switch in the service provider's network, the outer tag is stripped for packet
processing. When the packet exits another trunk port on the same core switch, the
same SPVLAN tag is again added to the packet.
When a packet enters the trunk port on the service provider's egress switch, the
outer tag is again stripped for packet processing. However, the SPVLAN tag is not
added when it is sent out the tunnel access port on the edge switch into the
customer's network. The packet is sent as a normal IEEE 802.1Q-tagged frame,
preserving the original VLAN numbers used in the customer's network.
Customer A
(VLANs 1-10)
VLAN 10
Tunnel Access Port
Tunnel Access Port
VLAN 20
Customer B
(VLANs 1-50)
Layer 2 Flow for Packets Coming into a Tunnel Access Port
A QinQ tunnel port may receive either tagged or untagged packets. No matter how
many tags the incoming packet has, it is treated as tagged packet.
The ingress process does source and destination lookups. If both lookups are
successful, the ingress process writes the packet to memory. Then the egress
QinQ Tunneling
Service Provider
(edge switch A)
Tunnel Uplink Ports
Double-Tagged Packets
Outer Tag - Service Provider VID
Inner Tag - Customer VID
VLAN Configuration
Service Provider
VLAN 10
(edge switch B)
Tunnel
Tunnel
VLAN 20
3
Customer A
(VLANs 1-10)
Access Port
Access Port
Customer B
(VLANs 1-50)
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