This topic describes the principles of data planning for Internet and Wi-Fi access services and will focus on the VLAN planning and VLAN translation policy planning in different network scenarios.
VLAN and VLAN Translation Policy

Table 1 Planning of VLANs and VLAN translation policies for Internet access service
Application Scenario
VLAN Plan
VLAN Translation Policy
Bridging+Voice ONT
Double-tagged VLAN
ONT: ONTs configure the VLAN and add the same C-VLAN tag to packets. All ONTs are in the same C-VLAN.
OLT: The OLT performs VLAN translation: C<->S+C'. The C'-VLAN of every ONT differs from each other.
Bridging ONT + HGW
Double-tagged VLAN
ONT: The upstream packets sent from the HGW carry user-VLANs and the ONT transparently transmits them.
OLT: The OLT translates the U-VLAN to S-VLAN+C-VLAN.
Gateway ONT
Double-tagged VLAN
ONT: ONTs configure the VLAN and add the same C-VLAN tag to packets. All ONTs are in the same C-VLAN.
OLT: The OLT performs VLAN translation: C<->S+C'. The C'-VLAN of every ONT differs from each other.
Table 2 Planning of VLANs and VLAN translation policies for Wi-Fi access service
Application Scenario
VLAN Plan
VLAN Translation Policy
Gateway ONT
Single-tagged VLAN
ONT: ONTs configure the VLAN and add the same C-VLAN tag to packets. All ONTs are in the same C-VLAN.
OLT: The OLT performs VLAN translation: C<->S.
Note:
User VLAN: VLAN carried by packets going upstream from user-side devices (such as a home gateway), U-VLAN for short.
C-VLAN: VLAN added based on the ONT/ONU port. For details, see the description of the Double-tagged VLAN S+C.
Double-tagged VLAN S+C: C indicates the inner VLAN (C-VLAN) and S indicates the outer VLAN (S-VLAN).
Double-tagged VLAN S+C': C' indicates the translated inner VLAN (C'-VLAN) and S indicates the outer VLAN (S-VLAN).
Single-tagged S-VLAN: Single-tagged VLAN marked or translated by the OLT. It is generally used in a single-tagged VLAN translation scenario.
C<->S+C': Bidirectional VLAN translation: translates the C-VLAN and then adds an S-VLAN.
C<->S+C: Bidirectional VLAN translation: maintains the C-VLAN and adds an S-VLAN.
NOTE:
To ensure traceability of users and finer-grained QoS control and management of users and services, plan per user per service per VLAN (PUPSPV) for the Internet access service. Considering OLT capacity and VLAN scalability, use dual VLANs (S-VLAN+C-VLAN) on the OLT to differentiate users for the Internet access service.
The outer VLAN (S-VLAN), which identifies services and physical location, can be allocated based on the OLT, PON board, or PON port. The inner VLAN (C-VLAN) identifies users. C-VLANs must be unique in one S-VLAN.
It is recommended that you use stacking VLANs as S-VLANs so that security features, such as PPPoE+/option82, and anti-MAC attacks and anti-MAC spoofing, can be easily deployed.
The 802.1q in 802.1q (QinQ) VLAN is used in the enterprise private line scenario, such as transparent LAN service (TLS), in which the device transparently transmits packets. It is not recommended that you use QinQ VLANs as S-VLANs for the triple play services of residential users.