H35-210_V2.5 Huawei HCIA-Access V2.5 Exam Free Practice Exam Questions (2025 Updated)

GPON (Gigabit Passive Optical Network) is a fiber-based access technology that supports downstream bandwidth up to 2.5 Gbps and upstream up to 1.25 Gbps, far exceeding the bandwidth capabilities of DSL technologies. ADSL (up to 8 Mbps), ADSL2+ (up to 24 Mbps), and VDSL (up to 100 Mbps over short distances) are copper-based technologies with significantly lower maximum bandwidth compared to GPON.

Querying Receive Optical Power :

Monitoring the receive optical power of an ONU is critical for troubleshooting and ensuring proper signal strength.

Command Analysis :

display ont optical-info : Displays detailed optical information for the ONU, including receive and transmit optical power.

display pon optical-info : Provides optical information for the entire PON port, not specific to individual ONUs.

display board : Shows hardware status of the OLT board, not optical power details.

display port state : Displays the operational state of ports, not optical power information.

Why A?

The display ont optical-info command is specifically designed to query the optical power of an individual ONU.

Thus, the correct answer is A .

References:

HCIA Huawei ACCESS Official Documentation , Chapter: ONU Optical Monitoring.

OLT Command Reference Guide by Huawei.

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 .

References:

HCIA Huawei ACCESS Official Documentation , Chapter: SNMP Configuration.

RFC 3411: SNMP Framework .

Let us analyze each protection scheme:

Type A Protection :

Protects only the trunk fiber (between the OLT and the splitter).

Does not protect branch fibers.

Type B Single-Homing Protection :

Protects the trunk fiber but does not extend protection to branch fibers.

Type B Dual-Homing Protection :

Similar to Type B single-homing but uses two OLTs for redundancy. Still does not protect branch fibers.

Type C Protection :

Provides end-to-end protection , covering both the trunk and branch fibers.

Uses redundant fibers and splitters to ensure continuity in case of failures in either the trunk or branch fibers.

Thus, the correct answer is D , as Type C protection is the only scheme that protects branch fibers.

References:

HCIA Huawei ACCESS Official Documentation , Chapter: GPON Protection Mechanisms.

GPON Redundancy and Protection Schemes by Huawei.

VLAN Tag Translation :

VLAN tag translation is used to modify VLAN tags in packets as they pass through the OLT.

The tag-transform parameter determines how VLAN tags are handled during service flow creation.

Behavior of tag-transform = default :

When tag-transform is set to default, the OLT applies predefined rules for VLAN tag conversion based on the SVLAN (Service VLAN) attributes.

These rules vary depending on the SVLAN type (e.g., Common, QinQ, Stacking), resulting in different behaviors.

Why TRUE?

The statement accurately reflects the behavior of the tag-transform parameter when set to default. Different SVLAN attributes lead to different tag conversion rules.

Thus, the correct answer is A .

References:

HCIA Huawei ACCESS Official Documentation , Chapter: VLAN Tag Translation.

OLT Configuration Guide by Huawei.

PPP Protocol Overview :

PPP (Point-to-Point Protocol) uses the PROTOCOL field in its header to identify the type of encapsulated protocol.

Protocol Field Values :

0x8021 : Indicates IPCP (Internet Protocol Control Protocol) , which is used to negotiate IP-related parameters during PPP session establishment.

0xC021 : Indicates LCP (Link Control Protocol) , which is used for establishing, configuring, and testing the PPP link.

0x002B : Indicates IPX (Internetwork Packet Exchange) .

0x0021 : Indicates IP (Internet Protocol) .

Why A?

The value 0x8021 corresponds to IPCP , making it the correct answer.

Thus, the correct answer is A .

References:

HCIA Huawei ACCESS Official Documentation , Chapter: PPP Protocol.

RFC 1661: PPP Protocol Specification .

NMS configuration requires:

A: Device name for identification.

B: SNMP community string for authentication.

C: IP address for communication.

D (Incorrect): Routing is handled by network devices, not NMS parameters.

B: Single-tagging requires matching service/user VLAN IDs.

C: VLAN-to-GEM mapping enables service segregation.

D: QinQ uses outer VLAN for aggregation and inner VLAN for user identification.

The Address Resolution Protocol (ARP) is used to map IP addresses to MAC addresses in a local network. ARP operates at the data link layer (Layer 2) of the OSI model and is essential for communication within a LAN.

ARP Request :

When a device needs to communicate with another device on the same network but does not know the destination's MAC address, it sends an ARP Request .

Since the sender does not know the MAC address of the destination, it cannot send the request directly to the destination using unicast. Instead, the ARP Request is sent as a broadcast packet to all devices on the local network.

The broadcast packet has a destination MAC address of FF:FF:FF:FF:FF:FF, which ensures that all devices on the network receive the packet.

ARP Response :

The device with the matching IP address responds with an ARP Reply , which is sent as a unicast packet back to the requesting device.

Why Not Other Options?

Anycast : This involves sending packets to the nearest device in a group of devices sharing the same IP address. ARP does not use anycast.

Unicast : ARP Requests cannot be sent as unicast because the sender does not yet know the destination's MAC address.

Multicast : Multicast is used for sending packets to a specific group of devices, but ARP Requests are sent to all devices on the network, making broadcast the correct choice.

Thus, ARP Requests are transmitted as broadcast packets .

References:

HCIA Huawei ACCESS Official Documentation , Chapter: ARP Protocol and Operation.

Ethernet Networking Fundamentals by Huawei.

DBA (Dynamic Bandwidth Allocation) :

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

Functions of DBA :

Improves upstream bandwidth utilization : DBA ensures efficient use of the limited upstream bandwidth by allocating it dynamically to ONUs as needed.

Does not increase total upstream bandwidth : The total upstream bandwidth of a PON port is fixed and determined by the hardware. DBA optimizes how this bandwidth is used.

Does not affect downstream bandwidth : Downstream bandwidth is shared via broadcasting and is not managed by DBA.

Does not add more ONUs : The number of ONUs supported by a PON port depends on hardware capacity, not DBA.

Why C?

DBA improves the efficiency of upstream bandwidth utilization by dynamically allocating resources.

Thus, the correct answer is C .

References:

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

GPON Dynamic Bandwidth Allocation by Huawei.

Downstream Transmission :

In GPON, downstream data is broadcast to all ONUs. However, each ONU only processes the data intended for it, identified by a unique identifier (ONU ID).

Upstream Transmission :

In the upstream direction, GPON uses TDMA (Time Division Multiple Access) to prevent collisions. Each ONU transmits data during its allocated time slot, and the optical splitter does not allow data from one branch fiber to interfere with another.

Why FALSE?

The second part of the statement is incorrect. Data from one branch fiber cannot be received by another branch fiber due to the TDMA mechanism and the design of the passive optical splitter.

Thus, the correct answer is B .

References:

HCIA Huawei ACCESS Official Documentation , Chapter: GPON Upstream and Downstream Transmission.

GPON System Architecture by Huawei.

OIDs (Object Identifiers) are numeric (e.g., 1.3.6.1.2.1.1.5), not letters. The statement in C is incorrect.

A: Weak optical power prevents ONT registration.

B: Auto-find must be enabled for ONT discovery.

D: Excessive optical power saturates the receiver.