Which indicators suggest a fiber cleanliness issue?

• A. Low latency and high throughput.
• B. High error rates, intermittent flaps, poor RX power
• C. Consistent signal with no errors.
• D. Need to replace fiber with longer length.

Answer: (B)

Fiber cleanliness directly affects optical signal integrity at the connector interface; dirt or contamination scatters light, increases insertion loss, and can cause reflections that lead to errors.

The clearest signs of a cleanliness issue are high error rates, intermittent link flaps, and poor RX power. High error rates occur when additional loss and noise degrade the signal-to-noise ratio, producing bit errors. Intermittent flaps happen when the contact quality changes due to contamination, causing sporadic loss of signal or fluctuating performance. Poor RX power indicates the receiver is receiving less light than expected, often due to extra loss from dirty connectors or ferrules.

Conversely, a healthy link shows low latency with high throughput and a consistent signal with no errors, which suggests clean, well-terminated connections. Replacing fiber with a longer length isn’t a cleanliness symptom; it affects the overall link budget and attenuation due to distance, not contamination at the connector.