Figure 9-5 802.1Q Encapsulation And Qinq Encapsulation; Figure 9-6 Networking Of Qinq-Based Bpdu Tunnels - Huawei Quidway S9300 Configuration Manual

Quidway S9300 Terabit Routing Switch
Configuration Guide - Ethernet
l
Issue 03 (2009-08-20)
an outer tag or a public tag and contains the VLAN ID of the public network. The inner tag
is usually known as the private tag and contains the VLAN ID of the private network.
NOTE
The QinQ function configured on a Layer 2 port is called VLAN stacking.

Figure 9-5 802.1Q encapsulation and QinQ encapsulation

802.1Q Encapsulation
DA SA ETYPE
6 Bytes 6 Bytes 2 Bytes
QinQ
Encapsulation
DA SA ETYPE
6 Bytes 6 Bytes 2 Bytes
QinQ-based BPDU tunnel

Figure 9-6 Networking of QinQ-based BPDU tunnels

LAN-B
MSTP
PE 1
CE-VLAN 100
CE-VLAN 200
PE-VLAN30:CE-VLAN 200~299
LAN-A
MSTP
When a large number of user networks are connected to the ISP network, many VLAN IDs
of the ISP are required if BPDUs are transparently transmitted through the VLAN-based
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TAG
LEN/ETYPE
2 Bytes 46 Byte~1500 Bytes
2 Bytes
TAG ETYPE TAG
2 Bytes 2 Bytes 2 Bytes
0x8100 Priority
PE-VLAN20:CE-VLAN 100~199
ISP Network
BPDU Tunnel
BPDU Tunnel
9 BPDU Tunnel Configuration
DATA FCS
4 Bytes
LEN/ETYPE DATA
2 Bytes 46 Byte~1500 Bytes
CFI VLAN ID
LAN-B
MSTP
PE 2
CE-VLAN 100
CE-VLAN 200
LAN-A
MSTP
FCS
4 Bytes
9-7