In order to ensure the traceability of users and the refined QoS control management based on users and services, Internet services are planned using PUPSPV (per user, service, and VLAN), and the…

Question

Options

• Asmart
• Bcommon
• CQinQ
• Dstacking

• A
  3% (1)
• B
  3% (1)
• C
  7% (2)
• D
  86% (25)

Explanation

Stacking is correct because this SVLAN attribute type causes the OLT to preserve the inner CVLAN tag while adding the outer SVLAN tag - creating a double-tagged (802.1ad-style) frame. This dual-tag structure is what enables PUPSPV: the SVLAN identifies the service, the CVLAN identifies the user/VLAN, giving the upstream network complete per-user, per-service, per-VLAN visibility for refined QoS enforcement.

Why the distractors are wrong:

• Smart (A): Maps multiple CVLANs to a single SVLAN, collapsing user distinction - useful for shared bandwidth pools, but breaks per-user traceability.
• Common (B): Replaces the CVLAN with the SVLAN (single-tagged), discarding inner VLAN info and eliminating the granularity PUPSPV requires.
• QinQ (C): While QinQ also involves double tagging, in Huawei OLT SVLAN terminology it refers to upstream tunnel aggregation - it doesn't deliver the per-user stacking behavior that PUPSPV demands.

Memory tip: Think of stacking as literally "stacking" two tags (SVLAN on top of CVLAN) - the two layers map directly to the two dimensions of PUPSPV traceability (service + user/VLAN). If you can see both tags, you can control both dimensions.

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