Huawei quidway s7700 - Concept of Qinq; Qinq Features Supported by the S7700; Configuring Qinq on an Interface; Establishing the Configuration Task

5.1 Concept of QinQ
This section describes the concept of QinQ.
The 802.1Q-in-802.1Q (QinQ) protocol is a Layer 2 tunneling protocol based on the IEEE
802.1Q technology. The frame transmitted on the public network has double 802.1Q tags. One
is a public tag and the other is a private tag. It is called the QinQ protocol.
The principle of QinQ is to encapsulate a private VLAN tag in a public VLAN tag; therefore, a
packet traverses the backbone network of the Internet service provider (ISP) carrying double
VLAN tags. By using the QinQ technology, the S7700 provides a simpler Layer 2 VPN tunnel
for users.
5.2 QinQ Features Supported by the S7700
This section describes the QinQ features supported by the S7700.
Selective QinQ
The S7700 supports selective QinQ, which is extended on the basis of QinQ. Selective QinQ
enables an interface to add the outer VLAN tags with different public VLAN IDs to frames
according to the private VLAN IDs in the inner VLAN tags. This can differentiate various types
of users.
The S7700 not only supports selective QinQ based on the interface and VLAN, but also supports
flow-based selective QinQ, 802.1p-based selective QinQ, and selective QinQ for untagged
packets.
For the commands related to flow-based selective QinQ, see the Quidway S7700 Smart Routing
Switch Command Reference - QoS.
Protocols Used by Outer VLAN Tags
The protocols applied to outer VLAN tags vary according to the vendors. To interwork with
non-Huawei devices, the S7700 supports the selective setting of the protocols used by the outer
VLAN tags.
Access to VLL, VPLS, and L3VPN Through Different Sub-interfaces
You can choose to access the VLL, VPLS, or L3VPN through different types of sub-interfaces
according to the networking.
Currently, only the E-series and F-series boards support sub-interfaces.
5.3 Configuring QinQ on an Interface
This section describes how to configure the interface type, the protocol used by the outer VLAN
tag, and the interface-based QinQ.
5.3.1 Establishing the Configuration Task
Quidway S7700 Smart Routing Switch
Configuration Guide - Ethernet 5 QinQ Configuration
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