H35-211_V2.5 Questions and Answers

In U2000’s IPTV/IGMP service model, the IGMP template suite includes: Permission templates (program authorization), Multicast user templates (user IGMP attributes), Program templates (program/group definitions), and Preview parameter templates (preview/fast-zapping parameters). These cooperate to control user authorization, program mapping, and IGMP behavior.

Huawei GPON design recommends at most two splitting stages and a total split ratio within the optical power budget (commonly up to 1:64 for standard budgets).

A: 1:2 × 1:16 = 1:32 (valid).

C: 1:8 × 1:8 = 1:64 (valid under standard budgets).

D: 1:2 × 1:8 = 1:16 (valid).

B: 1:16 × 1:16 = 1:256, which exceeds typical GPON budgets and recommended engineering practice. Hence B is the incorrect networking.

Drag & Drop Answer (NGN layers → devices):

Network control layer → Softswitch

Service management layer → OSS system

Edge access layer → MA5800

Core switching layer → Core router

Why:

Softswitch handles call/session control ⇒ control layer.

OSS provides O&M/service management ⇒ service management layer.

MA5800 is an OLT/access device ⇒ edge access layer.

Core router provides backbone forwarding ⇒ core switching layer.

For IP-based discovery, eSight relies on Layer-3 reachability and SNMP/ICMP. Being on the same subnet is not required; that condition applies to broadcast/ARP discovery. Required conditions include proper permissions, IP connectivity, and aligned SNMP parameters.

Huawei Anti-MAC-Spoofing binds the source MAC to the service flow/port to prevent address forgery. It is functionally exclusive with certain per-VLAN MAC check features (e.g., WMAC, SC, PPPoe-SMAC) to avoid conflicting validation logic. For IPoE users with fixed IP, operators typically configure static bindings/entries so that address and access policies remain consistent.

Option D is wrong: disabling Anti-MAC-Spoofing and removing fixed entries can affect service behavior; if forwarding is interrupted, that does impact user service—so the statement is self-contradictory and incorrect.

In NGN architectures, services (voice, video, data) converge over a packet-based backbone. The core switching layer provides the unified transport using IP/MPLS and related QoS mechanisms, delivering high reliability and large-capacity switching for all upper-layer services. The control and management layers orchestrate services, while the edge/access layer aggregates users—but the packet-based integrated transmission platform itself is the role of the core.

Standard OTDR operation allows you to configure multiple acquisition parameters:

Measurement range (distance range): sets the maximum span to be traced; best practice is typically 1.5–2× the fiber length under test.

Wavelength: select test wavelength(s), e.g., 1310/1550 nm for SM fiber, to observe different loss characteristics.

Mode: vendors provide real-time/average (or similar) acquisition modes to stabilize traces.

Pulse width: controls dynamic range vs. event resolution; longer pulses see farther but increase dead zones, while shorter pulses improve resolution at the cost of range.

These are documented in foundational OTDR references and application notes.

Per RFC 3261 (SIP), “The CSeq header field of the response MUST equal the CSeq field of the request.” CSeq carries a sequence number and the method, thereby associating a response with the specific request it answers. While Call-ID ties together all messages within the same dialog, it does not identify the specific request/response pairing; CSeq does. Therefore, CSeq is the correct header for correlating a response to the exact request.

SNMPv2c uses a community-string model (clear-text “read”/“write” strings) and provides no authentication integrity or encryption. Only SNMPv3 adds auth/privacy (AuthNoPriv/AuthPriv) with hashing and encryption. Therefore, stating that SNMPv2c can encrypt user passwords is false.

An Ethernet port protection group is a 1:1 protection mechanism that improves reliability through active/standby switching. It does not aggregate bandwidth—the standby port does not forward traffic unless a switchover occurs. If increased bandwidth is required, technologies such as LACP are used instead.

For IPv4 multicast, the MAC mapping uses 01-00-5E followed by the low-order 23 bits of the multicast IP address. Because an IPv4 multicast address has 28 variable bits (224/4), 5 bits are not mapped to the MAC. Therefore, 2⁵ = 32 distinct multicast IP addresses can map to the same multicast MAC address.

Type C dual-homing provides device-level protection with two OLTs; when one OLT/uplink fails, services switch to the peer OLT. In single-homing, ONUs are associated with only one OLT; therefore an OLT failure interrupts services (C). Single-homing has simpler networking and management than dual-homing (D). It does not offer switchover to another OLT (so B is incorrect), and the “important-service” positioning in A is typically applied to dual-homing scenarios that require the highest availability.

Huawei OLTs support ONT replacement without deleting the original service profile by using ONT replace/auto-find mechanisms. The OLT can bind the new ONT (new SN) to the existing ONT configuration template (service-port, VLAN, QoS, multicast profile, etc.), achieving a smooth replacement without manually removing and re-creating the ONT and services. The statement that you must remove the ONT and re-register from scratch is therefore wrong.

The OLT’s anti–IP-attack (control-plane protection) function identifies and rate-limits abnormal or attack traffic to protect the CPU. It does not block legitimate management protocols such as Telnet/SSH by design. Remote management remains available when sourced from permitted hosts and within configured thresholds; administrators can also use trusted-host/ACL policies if needed.

GPON traffic policing/shaping is commonly applied at multiple layers:

T-CONT rate control (T-CONT-CAR): controls upstream bandwidth per T-CONT.

GEM-port rate control (GEM-CAR): limits per GEM port.

Service flow rate control (Flow-CAR): enforces per-service policies.

GEM mapping is a forwarding association (service→GEM) and not itself a rate-control mechanism.

IPTV over FTTH relies on multicast control; therefore the essential U2000 template is the IGMP template, which defines IGMP behaviors, program authorization binding, and multicast parameters used by the OLT/ONT. MGC applies to voice (VoIP), and SNMP pertains to NMS communication rather than IPTV service logic; value-added templates are not mandatory for basic IPTV.

Huawei devices support independent mapping/remarking for inner and outer VLAN priorities (802.1p CoS) when QinQ is used. Operators can define distinct mapping tables or remark rules per tag. Option A is incorrect (priorities can be derived or remarked, not “must be” tag-in-packet), option C is incorrect because mapping profiles are configurable, and option D confuses VLAN IDs with priorities; inner/outer CoS can be mapped independently for inbound/outbound directions.

For Huawei uplink protection (STH-NNI port protection) with workmode timedelay, the mandatory steps are:

Create/define the protection group with the protect-target and workmode timedelay;

Add member ports with roles (work/protect);

Enable the protection group.

Interface-level timers like offline-tx-off-time under the physical interface are not required for standard timedelay protection operation and are therefore optional.

In capacity planning, the planned bandwidth is computed as:

Planned Bandwidth = Users × Penetration × Concurrency × Online Bandwidth × Duty Cycle × Channels × Coverage.

Substituting the values: 500 × 0.5 × 0.4 × 4 Mbit/s × 0.125 × 1 × 0.7

= 250 × 0.4 × 4 × 0.125 × 0.7

= 100 × 4 × 0.125 × 0.7

= 400 × 0.125 × 0.7

= 50 × 0.7

= 35 Mbit/s.

This matches the given result, so the statement is true.

Terminal (ONT/ONU/CPE) selection adheres to engineering principles: align model and interfaces with the deployment mode and scenario, evaluate TCO/cost, and satisfy special requirements (such as PoE, Wi-Fi specs, voice/FXS, industrial temperature). Ignoring project requirements is contrary to standard design workflows; therefore D is not correct.

OLT-level (device-level) protection is achieved by dual-homing ONUs to two independent OLT interfaces so that services can switch to another OLT when one fails. In Huawei protection taxonomy, the dual-homing scheme (as contrasted with single-homing) provides device-side redundancy for the OLT. By comparison, Ethernet port protection groups and LACP protect uplink links and bandwidth at Layer 2, not the OLT device itself; single-homing does not protect against OLT failure.

The ONT details pane in eSight displays access-port attributes (admin/state, type), Ethernet rate/speed/duplex, and PON optical module telemetry such as temperature and Tx/Rx optical power for condition monitoring and troubleshooting.

In IP multicast, only one copy per multicast group (program) is forwarded upstream, regardless of how many users are watching it. Replication happens downstream at the access/edge, not toward the core. Therefore the upstream traffic equals the number of active multicast groups × per-group bitrate:

20 programs × 2 Mbit/s = 40 Mbit/s.

This behavior is consistent with Huawei’s multicast feature descriptions and general multicast principles (IGMP/PIM), which explain that multicast traffic is sent as a single flow per group and replicated only where branching occurs, not multiplied by user count.

Huawei GPON service provisioning supports mapping upstream/downstream service flows to GEM Ports using multiple classifiers, including MAC address, physical port (PORT), VLAN ID, and 802.1p (priority). These classifiers are configured in line/service templates (and pushed via U2000) to ensure precise flow-to-GEM binding.

In IPTV/multicast access scenarios, channel zapping delay is heavily influenced by how fast the network stops forwarding the previous channel’s stream after a user switches. Huawei documents the IGMP Fast Leave/Prompt Leave feature, which enables the access device to immediately prune the old multicast group on receipt of a Leave (without waiting for group-specific queries and timers), thereby reducing the channel change delay and improving perceived switching speed. Option A explicitly disables a helpful pre-join optimization, which would worsen experience; Option C (preview) concerns showing brief previews and is not a primary mechanism for shortening zapping time; Option D is unrelated to performance. Thus, enabling Quick/Fast Leave is the correct action to shorten switching time.

According to IEEE 802.3av wavelength planning adopted by Huawei 10G-EPON, downstream uses 1577 nm and 10G upstream uses 1270 nm. In asymmetric coexistence, 1G-EPON upstream uses 1310 nm, but for 10G-EPON upstream specifically the wavelength is 1270 nm. Therefore the correct upstream wavelength for 10G-EPON is 1270 nm.

Type C GPON protection uses two different OLTs (dual-home). With uplink status linkage configured, a failure of the active OLT itself or its uplink interface triggers a protection switchover to the standby OLT to maintain service continuity for ONUs homed through the protected ODN.

When the number of access users approaches or exceeds the single-layer VLAN space and services must be distinguished per user, Huawei recommends hierarchical VLAN (QinQ) on the uplink: map a customer VLAN (C-VLAN) at the access side and add a service/provider VLAN (S-VLAN) toward the aggregation/core, i.e., C → S+C. This expands scalability beyond the ~4K single-VLAN limit while enabling precise user/service binding for large FTTH deployments (e.g., ~5K users under one OLT).

In Huawei’s QoS theory (aligned with IETF), the recognized service models are Best Effort, Integrated Services (IntServ), and Differentiated Services (DiffServ). FIFO is a queueing discipline (scheduling method) rather than a service model. FIFO simply forwards packets in arrival order without classification or guarantees, and while it can be used within Best Effort, it is not itself a service model.