NO.256 Which of the following statements about replacing the SCC board is incorrect?

• A. After the SCC board is removed, the BD_STATUS and COMMUN_FAIL alarms are reported. After the new board goes online, these alarms need to be manually cleared.
• B. If the software version of the new SCC board is later than equipment version, clear the database of the SCC board, and then downgrade the software on the SCC board to the same version as the equipment.
• C. If the software version of the new SCC board is earlier than the equipment version, upgrade the software on the SCC board to the same version as the equipment.
• D. In the case of the 1 + 1 hot backup of the SCC board, replacing the control board does not affect services when the active/standby switchover is performed.

NO.257 When different routes are used for client-side 1 + 1 protection, the working wavelength and protection wavelength cannot use the same wavelength.

• A. True
• B. False

NO.258 What are the wavelengths of the OSC channel used by the ST2 board?

• A. 1491nm
• B. 1510nm
• C. 1471nm
• D. 1511nm

NO.259 Which of the following statements about the line fiber quality monitoring performance parameters is wrong?

• A. Measurement is performed multiple times within the detection time. The average value is obtained based on the measurement results to improve the measurement precision. The actual duration from the time when a detection event starts to the time when the detection results are returned will be longer than the Detection time.
• B. When the pulse width increases, the light emitting time increases and consequently a larger energy is obtained. This means that a larger dynamic range can be acquired but also larger dead zones will result.
• C. The total fiber loss will affect the detection distance and the dynamic range is fixed for the same detection mode. Therefore, a larger total fiber loss indicates a smaller detection distance.
• D. The pulse width of emitted optical pulses varies according to monitoring modes, and affects the detection distance and measurement precision. A greater pulse width provides a larger dynamic range, longer detection distance and better measurement precision.

NO.260 Which of the following protection schemes require the APS protocol?

• A. SW SNCP
• B. ODUk SPRing protection
• C. 1:1 optical line protection
• D. ODUk SNCP

NO.261 MPLS tunnel APS protection supports multiple types of command switching and has different priorities. Which of the following command switching types has the highest priority?

• A. Manual Switching
• B. Force Switching
• C. Locked Switching
• D. Practice Switching

NO.262 Which of the following signals can be used as input or output signals of an external clock interface?

• A. 155 Mbit/s
• B. 2.048 MHz
• C. 2.048 Mbit/s
• D. 34 Mbit/s

NO.263 Which of the following alarms trigger optical line protection switching?

• A. POWER_DIFF_OVER
• B. R_LOF
• C. R_LOS
• D. MUT_LOS