3Com S7902E, Configuration Manual

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Basic Concepts of VLAN Mapping
Figure 1-1 Basic concepts of VLAN mapping
Before you configure VLAN mappings, be aware of the following concepts, which will be used
throughout this document.
z
Uplink traffic: Traffic transmitted from a user network to a distribution network or an SP network.
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Downlink traffic: Traffic transmitted from a distribution network or an SP network to a user network.
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Uplink port: A port transmitting uplink traffic and receiving downlink traffic.
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Downlink port: A port transmitting downlink traffic and receiving uplink traffic.
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Uplink policy: A QoS policy containing VLAN mappings for uplink traffic.
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Downlink policy: A QoS policy containing VLAN mappings for downlink traffic.
How VLAN Mapping Is Implemented
This section describes how VLAN mapping is implemented on your device.
One-to-one VLAN mapping
On the downlink port
For uplink traffic For downlink traffic
Do… Based on… Do… Based on…
Replace the
customer VLAN
(CVLAN) with the
service provider
VLAN (SVLAN)
Uplink policy in the
inbound direction
Replace the SVLAN
with the original
CVLAN
Downlink policy in the
outbound direction