Huawei H31-341_V2.5 HCIP-Transmission V2.5 Exam Practice Test

PWE3 specifies two CES emulation modes: Structure-Agnostic TDM over Packet (SAToP) and Structure-aware TDM Circuit Emulation Service over PSN (CESoPSN). Circuit Emulation over Packet (CEP) is not defined within PWE3.

The fixed attenuator is usually configured at the receive end, not the transmit end, to prevent the optical power at the receive end of an OTU (Optical Transport Unit) board from being excessively high. High optical power at the receiver can cause signal distortion or damage the receiver module. Configuring the attenuator at the receive end ensures that the incoming signal power is within the optimal sensitivity range of the receiver. Configuring attenuators at the transmit end is generally ineffective because it reduces power output before transmission, potentially reducing reach. This approach aligns with HCIP-Transmission best practices for optical power management and receiver protection.

A multimeter is used to verify the equipment’s electrical power and grounding.

An optical power meter measures the received optical power levels on each wavelength.

An optical spectrum analyzer checks the wavelength spacing, channel power, and spectral purity during WDM commissioning.

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.

Lower ground resistance indicates better grounding performance because it allows current to be conducted to the ground more quickly and efficiently. Good grounding is essential for equipment protection, system stability, and safety in transmission networks. A low resistance path reduces the risk of electrical shock, equipment damage, and signal interference. HCIP-Transmission underscores the importance of grounding quality as part of overall network infrastructure integrity and reliability, making low ground resistance a key objective in grounding design.

The TMB1AST2 board is a specialized optical module used in transmission equipment. According to HCIP-Transmission references, all the statements about this board are correct. (A) The TM1 optical port must be connected to the TMI1 optical port for proper operation. (B) It supports IEEE 1588v2 clock processing, essential for precise time synchronization, and includes OTDR (Optical Time Domain Reflectometer) functions for fiber fault detection and maintenance. (C) When working with DFIU03/DFIU04 boards, the OSC optical port requires an optical module that supports the 1511 nm wavelength to ensure wavelength compatibility. (D) Similarly, when working with DSFIU01/DSFIU02 boards, the TM1/RM1 and TM2/RM2 ports must use optical modules supporting 1511 nm and 1491 nm wavelengths respectively, ensuring correct wavelength assignment for WDM channels. This detailed configuration ensures interoperability and proper system functionality.

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

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 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.

PM (Performance Monitoring), TCM (Trail Channel Monitoring), and APS/PCC (Automatic Protection Switching/Path Connection Control) are defined ODUk overhead functions; NJO is not.

It is false that output optical power of a site must be as high as possible to ensure signals reach the peer site. Excessively high output power can cause nonlinear effects, such as four-wave mixing and self-phase modulation, degrading signal quality. Optimal power levels must be maintained within equipment specifications to balance reach and signal integrity. HCIP-Transmission stresses careful power management, including gain control and attenuation, to maximize network performance without introducing impairments.

In an OA (Optical Amplifier) system, the lower threshold of the receive optical power for a line board with a PIN receiver or the WDM side of an OTU board is typically the optical module’s receiver sensitivity plus 3 dB, not 5 dB. Adding 3 dB accounts for margin to ensure reliable reception without unnecessary overdesign. The 5 dB margin usually applies when an APD receiver is used, which is more sensitive but also more susceptible to noise. Thus, for PIN receivers, HCIP-Transmission guidelines specify the lower threshold as sensitivity plus 3 dB to maintain signal quality while preventing false alarms or unnecessary protection switching.

External faults (e.g., fiber cuts, connector issues) should be ruled out before investigating internal equipment faults.

Broader network-level checks (e.g., path continuity, OLP status) come before per-device NE diagnostics.

Isolate faults on individual wavelengths before examining the aggregated multi-wavelength transport.

Data dumping on Network Management Systems (NMS) can occur in several types: (A) Periodic dumping, where data is saved at set intervals for monitoring and analysis; (C) Overflow dumping, triggered when buffer capacity is exceeded; and (D) Manual dumping, initiated by user commands. (B) Automatic dumping is not a standard term here or is often encompassed within periodic or overflow dumping mechanisms. HCIP-Transmission references these types as part of NMS data handling and fault diagnosis strategies, enabling efficient network performance management and troubleshooting.

ODUk_PM_BDI refers to the ODUk PM backward defect indication. It is a monitoring signal used in OTN to indicate that a defect has been detected downstream (toward the transmitter side). When this indication is received, it informs the upstream node of the presence of defects or faults, allowing timely protection switching or troubleshooting. This mechanism supports fault propagation awareness across network segments, essential in maintaining service integrity. HCIP-Transmission details this indicator as part of ODUk performance monitoring (PM) overhead functions to enhance network reliability and fault management.

When light passes through a passive optical component, the decrease in optical power is termed insertion loss. This is a fundamental concept in optical transmission where every component like connectors, splices, splitters, or filters adds some level of power attenuation. Managing insertion loss is crucial to maintain overall system performance, especially in long-haul or dense WDM systems where accumulated loss can degrade the signal. HCIP-Transmission emphasizes the importance of measuring and minimizing insertion loss to ensure system stability and reach requirements are met.

In Link Aggregation Group (LAG) settings, port priority determines which ports carry traffic preferentially. (A) If a primary port is configured to preferentially carry services, it must have a higher priority than other ports to ensure it is selected first. Port priority is numerically represented, and (D) a lower value of “port priority” means higher priority, which can be counterintuitive but is standard in networking. For manual aggregation groups that don’t run LACP, priority settings typically do not apply. This priority mechanism helps optimize link utilization and failover in aggregated links, as detailed in HCIP-Transmission documentation on Ethernet and service aggregation.

In the described scenario, when the R_LOS alarm is detected on the client side at site A, after alarm processing on the WDM side, a REM_5F alarm is reported downstream at site B. Subsequently, site B reports an R_LOS alarm to its downstream client device, confirming alarm propagation and fault transparency in multi-site transmission. This behavior ensures that faults detected at one point are properly signaled through the network, allowing for coordinated protection and troubleshooting. HCIP-Transmission documents this alarm flow process in WDM site fault management and alarm handling procedures.

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

In ROADM terminology, a “colored” port is tied to a specific wavelength and cannot be tuned, so “colored” refers to fixed wavelength.

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

Deleting a path at the NE or network layer on the NMS does not itself interrupt service; the NMS operation is purely administrative and does not tear down traffic forwarding.

To prevent non-linear effects within dispersion compensation modules, the single-wavelength input power must not exceed –4 dBm.

The DWSS20 board does not support grooming of 20-degree optical signals; it is designed for other signal types or degrees.

RFC 4553 mandates the inclusion of the SAToP control word on every packet, so it is not optional.

The intermediate flatness method targets maintaining the single-wavelength input optical power within ±2 dB of the nominal value to ensure balanced power distribution and optimal system performance.

A single channel reporting the BEFFEC_EXC (Bit Error Forward Error Correction Excess) alarm can be caused by (D) the input optical power of an OTU board being too high or too low. Both extremes can degrade signal quality, causing excessive bit errors. Other causes such as signal attenuation, external environment issues, or faulty optical amplifiers can also impact performance but are less directly linked to BEFFEC_EXC alarms. HCIP-Transmission stresses maintaining proper optical power levels and equipment health to avoid such errors and ensure service quality.

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.

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.

After powering on, ensure the fan tray’s FAN indicator shows steady green (normal operation), fans are spinning properly, and airflow through both upper and lower parts of the subrack is unobstructed to maintain adequate cooling.

The TNG2WSMD09 board is a 9-port wavelength selective multiplexer/demultiplexer for the Super C band and supports optical power adjustment and online optical power detection.

Ensuring the downstream OA’s input is within the specified range by first reducing upstream EVOA attenuation is the standard first step when output power falls short at minimum gain.

If adjusting the EVOA does not bring the OA’s output into spec, increasing the OA’s gain is the next appropriate action.

When the OA meets output requirements at its minimum gain setting, the preceding fiber’s incident power must be at or above the lower limit defined by the incident-power specifications.