Radwin 2000+ SERIES, Руководство пользователя

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RADWIN 2000+ Series User Manual Release 4.2.40 15 ‐ 2
VLAN Tagging
15.4 VLAN Tagging
VLAN tagging enables multiple bridged networks to transparently share the same physical
network link without leakage of information between networks:
IEEE 802.1Q is used as the encapsulation protocol to implement this mechanism over
Ethernet networks.
15.4.1 QinQ (Double Tagging) for Service Providers
QinQ is useful for Service Providers, allowing them to use VLANs internally in their “transport
network” while mixing Ethernet traffic from clients that are already VLAN ‐ tagged.
The outer tag (representing the Provider VLAN) comes first, followed by the inner tag. In QinQ
the EtherType = 0x9100. VLAN tags may be stacked three or more deep.
When using this type of “Provider Tagging” you should keep the following in mind:
• Under Provider Tagging, the system double ‐ tags egress frames towards the Provider’s
network. The system adds a tag with a VLAN ID and EtherType = 0x9100 to all frames, as
configured by the service provider (Provider VLAN ID).
• The system always adds to each frame, tags with VLAN ID and EtherType = 0x9100.
Therefore,
• For a frame without a tag – the system will add a tag with VLAN ID and EtherType =
0x9100 so the frame will have one tag
• For a frame with a VLAN tag – the system will add a tag with VLAN ID and EtherType
= 0x9100 so the frame will be double ‐ tagged
For a frame with a VLAN tag and a provider tag – the system will add a tag with VLAN ID and
EtherType = 0x9100 so the frame will be triple ‐ tagged and so on.
At the egress side, the RT ‐ B(HSU) removes the QinQ tag with EtherType = 0x9100 no matter
what the value of its VLAN ID.
15.4.2 VLAN Untagging
VLAN Untagging means the removal of a VLAN or a Provider tag.
15.4.3 Port Functionality
In a 2000+ link, all VLAN activity is configured and supported from the RT ‐ B(HSU).
To this end, VLAN functionality is supported at the LAN port of the RT ‐ B(HSU).
The RT ‐ B(HSU) LAN port can be configured to handle Ethernet frames at the ingress direction
(where frames enter the RT ‐ B(HSU)) and at the egress direction (where frames exit the RT ‐
B(HSU)).