ACRF and PSACRF (ELFEXT and PSELFEXT)

The Attenuation to Crosstalk ratio Far-end (ACRF) measurement is a calculated value based on measured test results for FEXT and insertion loss. The Power Sum form of this test represents the combined effects of all three adjacent pairs on the test pair. Troubleshoot the associated crosstalk or insertion loss problem if this test fails. Table A-7 provides a more detailed listing of possible failure causes than found in Chapter 10.

Table A-7. Common ACRF and PSACRF test failure fault sources

Test Result	Possible Cause of Result
Fail, *Fail, or *Pass	General rule: troubleshoot NEXT problems first. This normally corrects any ACRF problems.
In addition to the NEXT and PSNEXT possible cause list, check for service loops with many tightly coiled windings