Copper Loop Qualifications and Troubleshooting Line Impairments

The following factors are affecting the performance of a copper pair and problems are increasing with the higher frequencies involved in ADSL/VDSL. The below conditions, should be tested when delivering  a new service or during fault diagnosis.

• Return Loss
• Insertion Loss
• Longitudinal Balance
• Crosstalk
• Noise
• Interruptions
• Split Pairs
• Gauge Changes
• Bridge Taps
• Bad Cable Twisting

xDSL- Loop qualification

Below some material found on the web ( webinars, application notes, white papers, articles etc.) on DSL troubleshooting , mostly from companies that manufacture xDSL Testing equipment.