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Avionics Full-Duplex Switched Ethernet (AFDX) is an avionics network patented by Airbus, developed starting with A380 and new standard in all new generation aircraft from Airbus factories.

I know that AFDX is Ethernet technology. But is it used the same Ethernet cable used to connect the computer to a LAN or to the Internet? Or is it used an improved version? Which are the differences between the two cables?

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    $\begingroup$ There are 7 levels of software and hardware commonly defined in networking standards. The top layer is called "application" and is the software you use, your browser, email etc. The bottom layer is called "physical" and is how the signals are transmitted from one place to another. The "Ethernet" standard defines what the physical layer must do, but not how it must do it. For example, Ethernet was invented and standardised long before WiFi which of course, transmits Ethernet signals with no cables at all. "Ethernet cable" doesn't mean much. You mean a cable which can carry Ethernet signals. $\endgroup$
    – Simon
    Commented Oct 3, 2016 at 20:44
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    $\begingroup$ I'm voting to close this question as off-topic because there is no explicit relationship to aviation. The OP needs to expand the acronyms, to make sure the relation is there, otherwise it's just a question about cable. $\endgroup$
    – CGCampbell
    Commented Oct 3, 2016 at 21:56
  • $\begingroup$ @Simon: Wi-fi doesn't relay Ethernet frames. Both Wi-fi and Ethernet are able to receive/deliver packets from the network protocol (often IP). While the OSI model is a reference, it doesn't depict well the TCP/IP world, it's more pre-IP and Telcos. $\endgroup$
    – mins
    Commented Oct 3, 2016 at 22:08
  • $\begingroup$ I agree that at first glance this question gives no evidence of being aviation related; it is however, since AFDX is an avionics network patented by Airbus. Voting to keep this open as on topic. $\endgroup$
    – J W
    Commented Oct 4, 2016 at 1:05
  • $\begingroup$ Thank you for editing the question to put the topicality to avionics forefront. Close vote is retracted. $\endgroup$
    – CGCampbell
    Commented Oct 4, 2016 at 21:25

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ARINC Specification 664 calls for quadrax cable or fiber optic cable. Quadrax is a four conductor matched impedance (100 ohm) cable. Connectors are MIL-DTL-38999.

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The primary benefit is improved EMI protection and ruggedized connectors.

The B787 uses fiber optic. A380 uses the quadrax cable.

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  • $\begingroup$ So, it's not Ethernet cable? Why is it called Avionic Full-Duplex Switched Ethernet, then? $\endgroup$ Commented Oct 3, 2016 at 14:10
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    $\begingroup$ It's not the same as the cable connected to your PC, but that's not the same cable in the walls (plenum rated), nor is it the coax used in 10base-2, yet they are all "Ethernet". $\endgroup$
    – Gerry
    Commented Oct 3, 2016 at 14:36
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    $\begingroup$ You could theoretically use standard Ethernet cables on an a/c, but they wouldn't pass environmental testing or reliability/durability. $\endgroup$
    – Gerry
    Commented Oct 3, 2016 at 14:48
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    $\begingroup$ Physical layers for Ethernet are not limited to twisted pairs and unfortunate 8P8C connectors, but are multiple. Interestingly ARINC didn't chose one of them. $\endgroup$
    – mins
    Commented Oct 3, 2016 at 15:34

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