Figure 4-3
Networking diagram of selective QinQ
PE1
P
PE2
CE2
CE1
Network
VLAN 10 to 50
Enterprise A
Branch 1
VLAN 10 to 50
Enterprise A
Branch 2
Data: VLAN 10 to 30
Voice: VLAN 31 to 50
21
31
to
50
20
10
to
30
20
10
t
o
30
21
31
t
o
50
21
31
to
50
20
10
to
30
20
10 to
30
21
31 to
50
Enterprise A has different services, so different VLANs are assigned. Data services are
transmitted in VLAN 10 to VLAN 30, and voice services are transmitted in VLAN 31 to VLAN
50.
Selective QinQ is configured on the user-side interface of the CE to add outer VLAN 20 to
packets with VLAN IDs 10 to 30, and outer VLAN 21 to packets with VLAN IDs 31 to 50, and
the device is configured to increase the priority of voice packets. Traffic between two branches
can be transparently transmitted through the public network so that users using the same service
in different branches of enterprise A can communicate, users using different services are isolated,
and voice services are transmitted preferentially.
4.2.4 TPID
The Tag Protocol Identifier (TPID) specifies the protocol type of a VLAN tag. The TPID value
defined in IEEE 802.1Q is 0x8100.
shows the Ethernet packet format defined in IEEE 802.1Q. An IEEE 802.1Q tag,
containing the TPID, lies between the Source Address field and the Length/Type field. A device
checks the TPID value in a received packet to determine whether the VLAN tag is an S-VLAN
tag or C-VLAN tag. The device compares the configured TPID value with the TPID value in
the packet. For example, if a frame carries the VLAN tag with TPID 0x8100 but the TPID
configured for a customer network on a device is 0x8200, the device considers the frame
untagged.
Huawei AR530&AR550 Series Industrial Switch Routers
Configuration Guide - Ethernet Switching
4 QinQ Configuration
Issue 01 (2014-11-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
126