H31-341_V2.5 Huawei HCIP-Transmission V2.5 Free Practice Exam Questions (2025 Updated)

Alarms prefixed with “SM” (Section Monitoring) - OTUk_SM_DEG and OTUk_SM_BDI - are specific to the OTUk section‐monitoring layer.

The term “Directioned” in WDM systems means that the wavelength carrying local services can be transmitted in a specific direction. This contrasts with directionless systems, where wavelengths can propagate in either direction without restriction. Directioned capability allows more controlled and secure wavelength routing, especially in ring or mesh networks where traffic flows need clear paths. Colorless refers to wavelength independence (a device can handle any wavelength), while colored means the device or port is assigned to a fixed wavelength. Thus, directioned accurately describes the wavelength propagation direction property as per HCIP-Transmission explanations on optical network design and wavelength routing.

Operations that generally interrupt services on live networks include (A) cold reset on a service board, (C) hardware loopback, and (D) software loopback. Cold reset reinitializes hardware and can disrupt traffic; hardware loopback physically loops the signal causing interruption; software loopback also reroutes signals internally, impacting live data flow. Warm reset, however, is designed to minimize or avoid service interruptions by restarting software processes without full hardware reinitialization. HCIP-Transmission emphasizes understanding these operational impacts for network maintenance planning to minimize service downtime.

In burst mode, an OTUk_DEG alarm is triggered when bit errors cause signal degradation, even if the error count threshold isn’t crossed.

In burst mode, the alarm also occurs if the number of bit errors within the detection window exceeds the configured threshold.

Optical layer overhead alarm detection is implemented via the Optical Layer Overhead Out Of Service (OOS) mechanism. Alarms like R_LOS (Loss of Signal) and MUT_LOS (Multiple Loss of Signal) belong to the optical layer and are reported based on OOS detection. This approach helps isolate physical layer faults and informs higher layers for protection switching or maintenance. HCIP-Transmission emphasizes that OOS-based alarm detection is crucial for rapid fault localization and efficient network operation in optical transmission systems.

The RDU9 board is used for demultiplexing optical signals; however, it cannot dynamically demultiplex any wavelength to any port. Dynamic demultiplexing requires advanced ROADMs or wavelength selective switches capable of flexible mapping. The RDU9 has limited fixed demultiplexing functions and does not support arbitrary wavelength-to-port assignments. Therefore, the statement that it can dynamically demultiplex any wavelength to any port is false. This aligns with HCIP-Transmission technical references highlighting the capabilities and limitations of different demultiplexing hardware modules.

When a receiver detects an OTUk_DEG (degraded) condition, it signals the upstream node by sending a backward defect indication (OTUk_BDI) alarm.

To find the nominal multiplexed input power when reducing from 80 to 10 wavelengths, use logarithmic power scaling:

Start with the minimum input power per wavelength (-16 dBm), subtract 10·log(10) to adjust for fewer wavelengths passing, then add 10·log(80) to scale back to the full 80-wavelength configuration.

The Optical Amplifier (OA) module inside an EMR8 board includes a critical function called "gain locking." This function ensures that when channels are added, dropped, or experience fluctuations, the gain of the remaining channels stays stable. Without gain locking, changes in one channel's power could inadvertently affect the amplification of other channels, causing signal degradation and uneven performance. Gain locking maintains consistent output power levels and improves overall system stability, which is vital in dense WDM networks. This function helps avoid cascading issues during dynamic network changes and supports reliable service delivery in HCIP-Transmission systems.

Among the differences between MPLS-TP OAM and MPLS OAM, the interval for sending OAM packets is not changed by canceling 3.3 ms and 10 ms values (D). This means these intervals remain in place or are not the key differentiators. The other options (A, B, C) correctly describe differences such as packet formats, label alarms (AIS, RD1, UNEXPMEG), and added functions (CC, AIS, LB, LT) unique to MPLS-TP OAM. HCIP-Transmission materials clarify these differences to aid in understanding the enhanced OAM capabilities for transport profile MPLS networks.

A ROADM (Reconfigurable Optical Add-Drop Multiplexer) site is a key component in flexible optical networks. It allows the flexible adding and dropping of wavelengths within the site (A), enhancing network agility. It supports automatic optical power adjustment (B), which helps maintain signal quality across the network by balancing power levels and avoiding distortion. Also, when optical-layer ASON (Automatically Switched Optical Network) is required, ROADMs must be used (C) to provide dynamic wavelength routing and switching capabilities. However, ROADMs are not mandatory for electrical-layer ASON, so (D) is false. These features collectively enable efficient, dynamic optical networking with minimal manual intervention, critical in advanced transmission scenarios covered by HCIP-Transmission.

An abnormal TTI in the SM layer triggers a Trail Identifier Mismatch (TIM) alarm. AIS signals loss of signal, not a TTI mismatch.

Signal flow analysis is a diagnostic method used to check the service flow through a faulty WDM system node by node, aiding in fault localization. By analyzing the signal path stepwise, engineers can identify where faults or performance degradation occur within the network elements. HCIP-Transmission materials highlight this technique as vital for efficient troubleshooting in complex optical networks, enabling fast restoration and minimal service impact.

The statement that the OA gain can be reduced when expanding 100G channels in a 10G system to meet incident optical power requirements is false. In fact, the single wavelength incident optical power of a 100G system is higher than that of a 10G system, and gain adjustment needs to ensure the 100G channels meet their power requirements without degradation. Reducing OA gain indiscriminately could cause insufficient amplification for 100G signals, impairing performance. HCIP-Transmission specifies careful power management and gain setting to balance multi-rate systems during hybrid transmission expansion.

In 1+1 optical line protection configurations, either the RI1/TO1 path or the RI2/TO2 path can be designated as the working channel.

R_LOS, R_LOF, R_OOF, and MUT_LOS all indicate loss of signal or framing, which directly interrupts service delivery.

The Multiframe Alignment Signal (MFAS) is specifically defined to provide alignment across multiple OTUk/ODUk frames when overhead bytes span those frames, so it must be used for multiframe alignment.

An advantage that is not true about OTN (Optical Transport Network) is that it provides a maximum of five levels of nested or overlapped TCM (Trail Connection Monitoring) connection monitoring (C). In reality, OTN provides powerful out-of-band FEC (Forward Error Correction), wide service interface support (from 2 Mbit/s to 400 Gbit/s), and meets the Tbit/s bandwidth requirements using WDM, but TCM monitoring is more limited. HCIP-Transmission clarifies that OTN’s strengths lie in scalability, error correction, and flexible service mapping, rather than extensive nested TCM levels.

ROADM networking has several key characteristics. (B) Existing services are not affected while the network is being upgraded because ROADMs support in-service wavelength reconfiguration, allowing maintenance and upgrades without service interruption. (C) The power equalization function enables channel-level power equalization, which balances the optical power of each wavelength to ensure signal quality and stability. However, (A) While network maintenance efficiency is improved with ROADM, it is not guaranteed that wavelengths can always be efficiently modified without cost implications, and (D) network construction costs are generally higher due to advanced hardware requirements. HCIP-Transmission highlights these features to showcase ROADM’s role in flexible, resilient optical networking with minimal disruption.