What are the key differences of Cat6 standards?

The key difference between the standards for Category 6A is the requirements for Near End Cross Talk (NEXT) performance. The ‘A’ in Category 6A means augmented, which means that the requirements for Category 6 are Augmented up to 500 MHz. With the ISO and EN standards the NEXT limit equation is simply extended above 250 MHz to 500 MHz using the same equation. The TIA standard relaxes the limit at 330 MHz.