ARINC664/AFDX vs COTS
"“AFDX”/ARINC-664 Part 7, or “Avionics Full Duplex Switched Ethernet”" is remarkably similar to dual-link UDP over a pair of classical switched Ethernets, and has been for a few years. Indistinguishable, in some circumstances.
I've even seen High Street network gear used (on the ground, for test/experimental purposes) when the real thing was temporarily unavailable.
However, there are some real differences (or used to be) such as hardware-enforced bandwidth limits, and when it's deployed in a real aircraft, you might expect it to be the dedicated flight-standard real thing, not the PC World/D-Link/Netgear/etc version.
The fact that the Airworthiness Directive references Ethernet rather than AFDX or ARINC664 is interesting. Yes I've looked at the source as well as the article. Maybe there was a time when EASA would have been more careful with terminology. Or maybe I'm misremembering - this 2008 article calls it out as Ethernet too:
"ARINC Specification 664 Part 7 defines AFDX. AFDX takes existing Ethernet physical layer technology and, using switched Ethernet in full-duplex mode as a basis, adds deterministic packet delivery, and high-integrity and high-availability mechanisms."