1.Receive signals of multiplexed wavelengths being abnormal
1)The line-side optical power is abnormal. For example, the receive optical power is excessively high or low.
2) The dispersion tolerance is insufficient. For example, the residual dispersion exceeds the permitted range.
3) The OSNR deteriorates.
4) The insertion loss is overlarge due to contamination of fiber connectors or pigtails.
5) The board, such as an OA board or multiplexed-wavelength processing board, malfunctions or the board performance deteriorates.
2.Receive signals of a single wavelength being abnormal
1) The receive optical power is abnormal. For example, the receive optical power is excessively high or low.
2) The dispersion tolerance is insufficient. That is, the residual dispersion exceeds the permitted range.
3) The insertion loss is overlarge due to contamination of fiber connectors or pigtails.
4) The board, such as a single-wavelength processing board, malfunctions or the board performance deteriorates.
5) The OSNR deteriorates or the channel power equilibrium is poor.
3.Environment
1) The optical cables are abnormal. For example, fibers have nonlinear effects or overlarge attenuation.2) The equipment operating environment is abnormal. For example, the ambient temperature is excessively high or low.
3) The board is incorrectly configured. For example, the service mapping mode or FEC mode is incorrectly configured.
4) The clock configuration is abnormal. For example, the clock is unstable or no clock is configured.
