Half-duplex connections were popular at the time of 10Mbps and 100Mbps Ethernet, and, according to standards, it is allowed also in case of 1Gbps Ethernet.
Am I correct that half-duplex mode support in Ethernet chipsets was crucial in case either a network hub (hub is internally a single wire) or some other shared Ethernet medium (for example, 10BASE-5) was used?
Are there any reasons for half-duplex connections in Ethernet environments where twisted-pair cabling is used and hubs are not used?
Best Answer
The reasons for half-duplex ethernet are as you understand them. In fact, there was a movement to not include half-duplex for 1000Base-T, but it still made it into the standard. For 10 Gb ethernet, half-duplex was dropped so there is no such thing as 10 Gbps half-duplex ethernet as a standard.
Unless you still have a hub (they are still around) or a device that doesn't support full-duplex (they exist, especially for 10Base-T), 10Base-T or 100Base-TX on UTP don't really need half-duplex.