Huawei Updated H35-211_V2.5 Exam Questions and Answers by juliette

GPON specifies data encryption (commonly AES-128) on downstream traffic so that one ONU cannot eavesdrop another’s data on the shared PON. This cryptographic protection is the standard, practical method to prevent monitoring on GPON access networks; the other options are operational workarounds, not normal GPON security mechanisms.

Huawei OLTs support Eth-Trunk (link aggregation) with two standard modes: Static aggregation and Dynamic aggregation (LACP). These provide bandwidth expansion and redundancy on NNI uplinks. “Automatic” is not a defined mode; and “manual” is not used as a separate mode name in OLT Eth-Trunk configuration.

IEEE 802.3av (10G-EPON) explicitly enables coexistence of 1G-EPON and 10G-EPON on the same outside plant (ODN) by separating downstream wavelengths (1G ~1480–1500 nm vs 10G ~1575–1580 nm) and using dual-rate TDMA in the upstream (10G uses 1260–1280 nm within the broader 1G band). This wavelength plan and OLT capabilities allow operators to reuse existing ODN and achieve a smooth upgrade via WDM overlays at the OLT. Industry and standards materials emphasize this approach for incremental migration.

A single-layer VLAN is limited by the IEEE 802.1Q VLAN ID space (1–4094), i.e., about 4K VLANs. In large PON deployments, when you must separate multiple services (e.g., HSI, VoIP, IPTV) and the user scale approaches or exceeds the 4K ceiling, a dual-layer VLAN (QinQ) design is required to extend the VLAN namespace and implement hierarchical isolation (access VLAN + service/aggregation VLAN).