Basic QinQ can choose the outer tag encapsulation method according to the business type.

The statement is incorrect. Basic QinQ, also known as port-based QinQ, is a static tunneling method. It adds the same, pre-configured outer VLAN tag (S-VLAN tag) to all frames that ingress a specific Layer 2 interface, regardless of the "business type" or the inner VLAN tag (C-VLAN tag) of the incoming frame. The functionality described in the question—choosing an outer tag based on the business type (typically represented by the inner VLAN ID)—is a characteristic of Selective QinQ (also known as flexible QinQ). Selective QinQ provides a more granular approach by allowing an administrator to map specific inner VLANs or a range of inner VLANs to different outer VLANs, thereby differentiating services.

The "True" option is incorrect because it misattributes the capabilities of Selective QinQ to Basic QinQ. The core principle of Basic QinQ is its simplicity and lack of granularity; it treats all traffic on a port uniformly by applying a single outer tag.

1. Huawei HedEx Documentation for CloudEngine S5732-H Series Switches: In the feature description for QinQ, the documentation clearly distinguishes between the two types.

Basic QinQ: "Basic QinQ is implemented based on interfaces. After basic QinQ is enabled on an interface, the switch adds the default VLAN tag of this interface to all the packets passing through the interface." This confirms the static, non-selective nature.

Selective QinQ: "Selective QinQ is implemented based on VLAN IDs. You can specify the inner VLAN IDs of packets to be tagged with an outer VLAN tag." This confirms the ability to choose based on traffic characteristics.

Source: Huawei CloudEngine S5732-H Series Switches Documentation, Section: Feature Description > VLAN > QinQ.

2. Huawei HCIP-Datacom-Advanced Routing & Switching Technology V1.0 Training Material: The official courseware for the H12-831 exam details the different QinQ implementations.

It describes Basic QinQ as a method where an interface is configured as a dot1q-tunnel port, and all received frames are encapsulated with the port's default VLAN ID (PVID) as the outer tag. This is a 1:1 mapping for the entire port.

It then introduces Selective QinQ as a more flexible method that allows mapping one or more customer VLANs (C-VLANs) to a service provider VLAN (S-VLAN), enabling service differentiation. The configuration involves commands like qinq vlan-translation, which explicitly maps inner VLANs to outer ones.

Source: Huawei HCIP-Datacom-Advanced Routing & Switching Technology V1.0 Training Material, Module: "Ethernet Switching Technology", Chapter: "VLAN Technologies", Section: "QinQ".