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Test Result Possible Cause of Result
FAIL or PASS* • Poor twisting at connection points
• Poorly matched plug and jack (Category 6/Class E
applications)
• Incorrect link adapter (Cat 5 adapter for Cat 6 links)
• Poor quality patch cords
• Bad connectors
• Bad cable
• Split pairs
• Inappropriate use of couplers
• Excessive compression caused by plastic cable ties
• Excessive noise source adjacent to measurement
Unexpected PASS • Knots or kinks do not always cause NEXT failures,
especially on good cable and far removed from the ends
of the link
• Incorrect autotest selected (e.g. “Bad” Cat 6 link
tested to Cat 5 limits)
• “Fails” at low frequency on NEXT graph but passes
overall. When using the ISO/IEC standards, the so
called 4dB rule states all NEXT results measured while
insertion loss <4dB cannot fail
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