Huawei H35-210_V2.5 HCIA-Access V2.5 Exam Practice Test

Answer : A

In a PON system, the OLT (Optical Line Terminal) and ONU (Optical Network Unit) use Ethernet interfaces externally to connect to the service provider's network and end-user devices, respectively. Internally, the PON uses GEM (GPON Encapsulation Method) frames to encapsulate and decapsulate data for transmission over the optical distribution network (ODN).

Answer : B

Default Behavior of ONUs :

By default, ONUs (Optical Network Units) connected to the same PON port of a Huawei OLT are isolated at Layer 2 .

This isolation ensures that ONUs cannot communicate directly with each other, even if they belong to the same service VLAN.

Why FALSE?

The statement incorrectly claims that ONUs can communicate with each other at Layer 2 by default. In reality, Layer 2 isolation is a security feature designed to prevent unauthorized communication between ONUs.

Enabling Communication :

If Layer 2 communication between ONUs is required, it must be explicitly enabled through configuration (e.g., by disabling Layer 2 isolation).

Thus, the correct answer is B .

HCIA Huawei ACCESS Official Documentation , Chapter: GPON Security Features.

OLT Configuration Guide by Huawei.

Answer : B

Vectoring Classification :

Vectoring is primarily classified into two types based on the scope of crosstalk cancellation:

System-Level Vectoring (SLV) : Applies to all lines within a single DSLAM or cabinet.

Node-Level Vectoring (NLV) : Applies to lines across multiple DSLAMs or nodes.

However, these are not the only classifications. Other implementations, such as hybrid approaches, may also exist depending on the network design.

Why FALSE?

The statement incorrectly claims that vectoring is classified only as SLV and NLV, ignoring other possible implementations or variations.

Thus, the correct answer is B .

HCIA Huawei ACCESS Official Documentation , Chapter: VDSL2 Vectoring Architectures.

ITU-T G.993.5 Standards for Vectoring in VDSL2 .

Answer : A, C

Let us analyze each statement carefully:

Option A :

Incorrect : In inter-VLAN communication, hosts in different VLANs cannot directly communicate with each other because VLANs are isolated at Layer 2. Communication between VLANs requires a Layer 3 device (e.g., a router or Layer 3 switch).

Hosts do not learn the MAC addresses of devices in other VLANs. Instead, they communicate through a gateway (router or VLANIF interface), and the gateway handles the forwarding.

Option B :

Correct : A VLAN is indeed a broadcast domain . Devices within the same VLAN share the same broadcast traffic, while devices in different VLANs do not.

Option C :

Incorrect : A VLAN is not a collision domain. Collision domains are defined at the data link layer (Layer 2) and are associated with individual switch ports or hubs. VLANs are logical groupings that span multiple switch ports and do not represent collision domains.

Option D :

Correct : VLANIF interfaces (also called Switch Virtual Interfaces, SVIs ) are logical Layer 3 interfaces configured on switches to enable inter-VLAN routing. These interfaces allow communication between VLANs by acting as gateways for each VLAN.

Thus, the incorrect statements are A and C .

HCIA Huawei ACCESS Official Documentation , Chapter: VLAN Fundamentals.

Inter-VLAN Routing and VLANIF Interfaces by Huawei.

Answer : A, C, D

Dynamic Bandwidth Assignment (DBA) :

DBA is a key mechanism in GPON systems that dynamically allocates upstream bandwidth among ONUs based on their traffic demands.

Functions of DBA :

To provide high-bandwidth services : DBA ensures that ONUs can access sufficient bandwidth for high-priority or bursty traffic, such as video streaming or large file uploads.

To avoid optical signal conflicts : This is achieved through TDMA (Time Division Multiple Access), not directly by DBA. DBA focuses on bandwidth allocation rather than collision avoidance.

To improve upstream bandwidth utilization : By dynamically allocating bandwidth, DBA ensures efficient use of the limited upstream capacity of a PON port.

To dynamically allocate upstream bandwidth : DBA operates in real-time, adjusting bandwidth allocations within microseconds or milliseconds to meet changing traffic demands.

Why A, C, D?

These options accurately describe the functions of DBA. Option B is incorrect because avoiding optical signal conflicts is handled by TDMA, not DBA.

Thus, the correct answers are A, C, D .

HCIA Huawei ACCESS Official Documentation , Chapter: GPON DBA Mechanism.

ITU-T G.984.x Standards for GPON .

Answer : A

Answer : C

SNMP Trap Source Address :

The trap source address is the IP address used by the device to send SNMP traps to the NMS (Network Management System).

Configuration Options :

Option A : Setting the trap source address to 127.0.0.1 (localhost) is incorrect because it is not routable and cannot be used for communication with the NMS.

Option B : Using the loopback address is possible but not recommended unless the NMS is explicitly configured to accept traps from the loopback address.

Option C : Setting the trap source address to the same address used by the NMS to add the device ensures proper communication and alignment between the device and NMS.

Option D : Incorrect because not all options are valid.

Why C?

Configuring the trap source address to match the address used by the NMS ensures that the NMS can correctly identify and process traps from the device.

Thus, the correct answer is C .

HCIA Huawei ACCESS Official Documentation , Chapter: SNMP Configuration.

RFC 3411: SNMP Framework .