ACMC - Alien Crosstalk Margin Computation

Alien Crosstalk Margin Computation applies to 10GBASE-T, TIA TSB-155 and TR 24750 ONLY. It does not apply to Augmented Category 6 or Class EA.

The PS AXtalk average margin computation consists of the (power) summation of PS ANEXT and PS AFEXT (that includes power backoff for each ANEXT and AFEXT measurement) minus the (power) summation of PS ANEXT limit and PS AACR-F limit + measured IL of the disturbed link averaged over the 10 MHz to 400 MHz frequency range.

Practically speaking, this may cause overall alien crosstalk measurements to pass, even if a particular PS ANEXT or PS AACR-F test or set of tests fail. An example of this can be found in here.