Chapter 1 Qinq Configuration; Qinq Overview; Introduction To Qinq - H3C S7500 Series Operation Manual

Operation Manual – QinQ
H3C S7500 Series Ethernet Switches

Chapter 1 QinQ Configuration

1.1 QinQ Overview

1.1.1 Introduction to QinQ

The QinQ function enables packets to be transmitted across the operators' backbone
networks with VLAN tags of private networks encapsulated in those of public networks.
In public networks, packets of this type are transmitted by their outer VLAN tags (that is,
the VLAN tags of public networks). And those of private networks which are
encapsulated in the VLAN tags of public networks are shielded.
Figure 1-1
0
Figure 1-1 Structure of a single-tagged packet
Figure 1-2
0
Figure 1-2 Structure of a double-tagged packet
Compared with MPLS-based Layer 2 VPN, QinQ has the following features:
It provides simpler Layer 2 VPN tunnels.
QinQ can be implemented through static configurations only, without the support
of signaling protocols.
The QinQ function provides you with the following benefits:
Saves public network VLAN ID resources.
illustrates the structure of a single-tagged packet.
Destination MAC address
illustrates the structure of a double-tagged packet.
Destination MAC address
15
Source MAC address
VLAN Tag
Data
15
Source MAC address
Outer VLAN Tag
Inner VLAN Tag
Data
1-1
Chapter 1 QinQ Configuration
31
31