User's Manual

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Example 2
If different services of a same user are dealt with and the access terminal of a user connects the UNI
port of PE, the Dot1Q tunnel VLAN translation must be used to differentiate different services and carry
different QoS standards.
As shown in figure 8, the carrier distributes three VLANs for each user and each VLAN corresponds to
a kind of service. For example, user 1 is distributed with 3 VLANs, that is, VLAN 1001, VLAN 2001 and
VLAN 3001, among which VLAN 1001 is for broadband services, VLAN 2001 is for VoIP services and
VLAN 3001 is for IPTV services. When a service reaches the UNI port of the PE switch, an out-layer
label will be added to the service according to its VLAN ID (different services are added with different
outer-layer labels). If the out-layer label of the user data is 1001, the user data will be added with label
1001 directly on its outer layer. As to user 2, different services can be distributed with different VLAN
tags. The outer-layer tag of user 2 is different from that of user 1 mainly for differentiating the location of
CE and also locating users.
Device
Servic
e
Inner-layer CVLAN
tag
Outer-layer SPVLAN
tag
Flow
classification
principle
CE1
broadb
and
101-200 1001
CVLAN domain
VOIP 201-300 2001
IPTV 301-400 3001
CE2
broadb
and
101-200 1002
VOIP 201-300 2002
IPTV 301-400 3002
In this networking solution, the two layers of tags differentiate services very well and locate users.
The outer-layer tag identifies the location of CE and a service, while the inner-layer tag identifies
the location of a user.