US What the A in Cat6A means
Cat6 vs Cat6A compares two grades of twisted-pair Ethernet cable defined in TIA-568. The A stands for augmented. Cat6A was published in 2008 to carry 10GBASE-T, the 10 Gb/s copper Ethernet that IEEE 802.3an defined in 2006, the full 100 m. In ISO/IEC 11801 terms, Cat6 cabling is Class E and Cat6A is Class EA.
Cat6A doubles the test frequency to 500 MHz and, more importantly, adds a requirement that Cat6 never had: limits on alien crosstalk, the interference one cable picks up from the cables bundled alongside it.
Alien crosstalk and 10 Gb/s
At gigabit speeds, the main noise in a cable comes from its own pairs, and Cat6 controls that well. At 10 Gb/s, the signal uses frequencies up to around 400 MHz, and the cables next to it in a tray become the bigger problem. Because that noise comes from other cables, the network card cannot cancel it the way it cancels crosstalk inside the cable.
Cat6 has no alien crosstalk limit, so its 10GBASE-T reach depends on how tightly it is bundled: typically around 55 m in good conditions and nearer 37 m in dense bundles. TIA’s TSB-155 sets out how to test an existing Cat6 run for 10 Gb/s. Cat6A controls alien crosstalk with greater spacing between cables, a larger jacket or a shield, so 100 m is assured.
Cat6 and Cat6A compared
The table sets the two cables side by side on the points that decide an installation.
| Feature | Cat6 | Cat6A |
|---|---|---|
| Tested to | 250 MHz | 500 MHz |
| 10GBASE-T reach | Around 37 to 55 m | 100 m |
| Alien crosstalk limit | None | Specified |
| Typical diameter, unshielded | Around 6 to 6.5 mm | Around 7.5 to 8.5 mm |
| Common construction | Mostly U/UTP | U/UTP or F/UTP |
| Heating in large PoE bundles | Moderate | Lower |
| Connectors | Cat6 RJ45 | Cat6A RJ45, M12 X-coded |
Both use RJ45 and are fully compatible with each other and with Cat5e equipment. A link performs to the lowest-rated part in it, so Cat6A cable needs Cat6A jacks, panels and patch leads.
Shielded or unshielded Cat6A
Cat6A is made both ways. Unshielded U/UTP Cat6A meets alien crosstalk limits through size, with a thick jacket that keeps neighboring cables apart. Shielded F/UTP Cat6A wraps the four pairs in foil, which blocks alien crosstalk directly and allows a slimmer cable. Shielded cable also rejects interference from drives and motors, so it is the usual choice on industrial sites, but the shield only works when it is bonded to earth through shielded jacks at the equipment.
Installing Cat6A
The extra performance comes with practical costs that are easy to underestimate at the planning stage.
- Containment. Cat6A’s larger diameter means noticeably fewer cables per tray, conduit or gland than Cat6, so size containment for it from the start.
- Bend radius and weight. The cable is stiffer and heavier, so it needs wider bends, more support on long vertical runs and more room behind patch panels and wall boxes.
- Termination. Cat6A jacks take longer to terminate, and shielded versions must be bonded correctly. Every link should be certified with a tester that measures to 500 MHz.
- Industrial connectors. On vehicles and machines, X-coded M12 connectors carry Cat6A performance with screw locking and IP67 sealing.
For a wider view of the categories, including Cat5e, our page on Cat5, Cat5e, Cat6 and Cat6A compared sets out speed and reach for each.
When Cat6A is worth installing
Cat6A costs more, takes up more containment and is harder to terminate than Cat6, so it pays where its extra headroom will be used.
-
//
10 Gb/s links over around 50 m. Server, storage and edge AI uplinks that will run at 10 Gb/s, or are likely to during the life of the cabling. Our 10GbE and PoE frame grabber cards bring multi-camera vision traffic into a computer over 10GBASE-T.
-
//
Multi-gigabit access points. Wi-Fi 6E and Wi-Fi 7 access points often have 2.5, 5 or 10 Gb/s uplinks, and Cat6A leaves room for the next generation. Our explainer on how wireless access points connect to the network covers uplinks and power.
-
//
High-power PoE bundles. Cat6A runs cooler than Cat6 when many cables carry 60 W or 90 W PoE together. Our comparison of PoE, PoE+ and PoE++ power levels sets out the budgets.
-
//
Machine vision and edge AI. Several high-resolution cameras can saturate 2.5 Gb/s, as our white paper on why edge AI is moving beyond 2.5GbE explains.
Quick answers on Cat6 vs Cat6A
Cat6 and Cat6A: common questions
Is Cat6A better than Cat6?
For 10 Gb/s, yes. Cat6A carries 10GBASE-T the full 100 m and runs cooler with PoE. For gigabit and 2.5 Gb/s links, the two perform the same.
Can I use Cat6A instead of Cat5e or Cat6?
Yes. Cat6A is backward compatible with every earlier category and uses the same RJ45 connector. It is simply thicker and stiffer to install.
Does Cat6A support PoE?
Yes, every IEEE PoE type. Cat6A carries PoE, PoE+ and PoE++ up to 90 W at the source, and its lower resistance reduces heating in large bundles.
Are Cat6 and Cat6A connectors the same?
Same type, different rating. Both use RJ45, but Cat6A plugs and jacks are built and tested for 500 MHz and often accept thicker cable. Use connectors rated for the cable.
Is Cat7 better than Cat6A?
Not for RJ45 networks. Cat7 is an ISO class that needs non-RJ45 connectors to reach its rating and is not recognized by TIA. Cat6A is the usual choice for 10 Gb/s copper.
We fit the 10GbE ports, network cards and connectors each system needs as standard, over Cat6A copper or SFP+ fiber, and test every link before the system ships.