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

Answer : B

MAC (Media Access Control) addresses are 48-bit identifiers assigned to network interfaces for communication on a local network.

Allocation of MAC Addresses :

MAC addresses are not allocated by the IETF . Instead, they are managed and assigned by the IEEE (Institute of Electrical and Electronics Engineers) .

The IEEE assigns blocks of MAC addresses to hardware manufacturers (vendors), who then assign unique MAC addresses to their devices.

Structure of MAC Addresses :

The first 24 bits (Organizationally Unique Identifier, OUI) identify the manufacturer.

The remaining 24 bits are assigned by the manufacturer to ensure global uniqueness.

Why FALSE?

The statement incorrectly attributes the allocation of MAC addresses to the IETF, which is responsible for Internet standards like TCP/IP, not MAC address allocation.

Thus, the correct answer is FALSE .

HCIA Huawei ACCESS Official Documentation , Chapter: MAC Addressing.

IEEE OUI Assignment Process .

Answer : A

Huawei's broadband access network devices are designed to support multiple technologies for providing connectivity to end users. These devices primarily include:

Copper Line Access Devices : These devices use xDSL (Digital Subscriber Line) technology, which is widely used for broadband access over traditional telephone lines. Examples include ADSL, VDSL, and G.fast.

Optical Access Devices : These devices use PON (Passive Optical Network) technology, which is a fiber-optic-based access technology. GPON (Gigabit Passive Optical Network) and XGS-PON (10-Gigabit Symmetric Passive Optical Network) are examples of PON technologies.

The statement aligns perfectly with the HCIA Huawei ACCESS documentation, which emphasizes the role of access-layer devices in supporting both copper and fiber-based technologies.

HCIA Huawei ACCESS Official Documentation , Chapter: Access Technologies Overview.

GPON and xDSL Technology Whitepaper by Huawei.

Answer : C

Vectoring in VDSL2 :

Vectoring is a technology used to mitigate crosstalk (interference between adjacent copper lines) in VDSL2 systems, improving data rates and stability.

Crosstalk occurs when signals from one line interfere with signals on another line, especially in bundled copper cables.

Pre-coder Technology :

Pre-coding is a key technique used in vectoring for downstream transmission.

It works by pre-distorting the transmitted signal at the DSLAM (Digital Subscriber Line Access Multiplexer) to cancel out the expected crosstalk at the receiver (CPE).

This ensures that the received signal at each CPE is free from interference caused by other lines.

Other Options :

fdps : Not a recognized term in the context of vectoring or VDSL2.

Canceller : While cancellation is part of vectoring, the specific term 'Canceller' is not used in this context.

Postponed : This is unrelated to vectoring or crosstalk mitigation.

Why C?

Pre-coding is the correct technology used in vectoring to cancel downstream crosstalk in VDSL2.

Thus, the correct answer is C .

HCIA Huawei ACCESS Official Documentation , Chapter: VDSL2 Vectoring.

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

Answer : B

Dynamic Bandwidth Assignment (DBA) :

DBA dynamically allocates upstream bandwidth among ONUs based on their traffic demands. Different DBA types are used for different service requirements.

DBA Types :

Type 1 : Fixed bandwidth allocation, suitable for constant bit-rate services like voice.

Type 3 : Mixed allocation, combining fixed and assured bandwidth. It is commonly used for AR (Assured Rate) services, which require guaranteed minimum bandwidth with flexibility for additional bandwidth.

Type 4 : Best-effort allocation, suitable for non-critical services like web browsing.

Why B?

Type 3 is specifically designed for AR services, providing both guaranteed and flexible bandwidth allocation.

Thus, the correct answer is B .

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

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

Answer : A

GPON networks use various protection mechanisms to ensure high availability and reliability. These mechanisms are classified into different types based on their scope and functionality:

Type A :

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

Does not protect branch fibers (between the splitter and ONUs).

Type B :

Protects the trunk fiber but does not provide simultaneous protection for branch fibers.

Type C :

Provides full protection for both the trunk and branch fibers.

Uses redundant fibers and splitters to ensure continuity in case of a failure.

Type D :

Not a standard GPON protection type.

Since the question specifies protection for both the backbone (trunk) and branch fibers, the correct answer is Type C .

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

GPON Redundancy and Protection Schemes by Huawei.

Answer : C

DHCP Relay Agent Functionality :

A DHCP relay agent forwards DHCP packets between clients and servers located in different subnets.

It modifies the packet headers to ensure proper delivery:

Converts broadcast packets from clients into unicast packets to forward them to the DHCP server.

Converts unicast responses from the DHCP server back into broadcast packets for delivery to clients.

Why C?

The DHCP relay agent performs bidirectional conversion between broadcast and unicast packets to facilitate communication between clients and servers in different subnets.

Other Options :

A : Incorrect because DHCP relay agents do not convert packet types (e.g., Ethernet vs. non-Ethernet).

B : Incorrect because the relay agent handles both broadcast-to-unicast and unicast-to-broadcast conversions.

D : Incorrect because the relay agent modifies unicast packets during forwarding.

Thus, the correct answer is C .

HCIA Huawei ACCESS Official Documentation , Chapter: DHCP Relay Agent.

RFC 2131: DHCP Protocol Specification .

Answer : D

Bridging ONU Configuration :

A bridging ONU acts as a transparent bridge between the PC and the OLT, forwarding traffic without modifying it.

VLAN Configuration for ETH1 :

VLAN 1 : The default VLAN, often reserved for management purposes. Using it for Internet access is not recommended.

Default Configuration : Leaving the port unconfigured may result in improper VLAN tagging or untagged traffic, leading to connectivity issues.

VLAN 4094 : Typically reserved for special purposes (e.g., QinQ termination) and is not suitable for general Internet access.

Native VLAN : Configuring a native VLAN ensures that untagged traffic from the PC is associated with the correct VLAN for Internet access.

Why D?

Configuring a native VLAN is the correct approach to ensure proper VLAN tagging and seamless Internet access for the PC connected to ETH1.

Thus, the correct answer is D .

HCIA Huawei ACCESS Official Documentation , Chapter: VLAN Configuration.

GPON Bridging ONU Configuration Guide by Huawei.