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p4bl0yesterday at 10:02 AM2 repliesview on HN

Thanks. So the author's point in the linked article is wrong, it's the opposite of what they wrote. Contrary to what they say, it's indeed a bus, and it isn't the case that CSMA/CD is useless, it's that isn't enough to deal with the situation, so additions have been made to it.

Thanks for your link that helped clarifying this for me!


Replies

okanatyesterday at 10:51 AM

When you have switches that link two nodes together, for only the duration of one-way transmission you don't need CSMA/CD. We literally have no use for it. We will never have two computers transmit onto the same Ethernet wire anymore.

WiFi is different of course. However as the author wrote, your WiFi devices always go through the access point where they use 802.11 RTS/CTS messages to request and receive permission to send packets. All nodes can see CTS being broadcasted so they know that somebody is sending something. So even CSMA/CA is getting less useful.

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noselasdyesterday at 11:19 AM

Not really. Wifi does not do CSMA/CD. It does CSMA/CA, something quite different.

Wifi is in any case not considered a bus network, rather a star topology network.