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Discussion on: Is there such a thing as "Full Duplex" in an Ethernet environment?

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riturajborpujari profile image
Rituraj Borpujari • Edited

You are right. The ability to have full duplex is point to point logically direct connections.
Fortunately, NICs, which obviously has only one hardware MAC address, can have separate send and receive paths. They can use them at the same time without collision.
In half duplex, they use CSMA/CD to avoid collision. But this is unnecessary for full duplex mode.
So ethernet NICs are able to operate in full duplex mode.
However, not all medium can support this. For eg, coaxial cable cannot operate in full duplex mode, but fiber can.

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jwp profile image
John Peters • Edited

Oh yes as in crossover cable... forgot that part. New summary

  • Full Duplex must have a logically directs connection to the other side.
  • Full Duplex does not use CSMA
  • MAC addresses can send and receive at same time (e.g. CrossOver Cable) because there are two channels in twisted pair wires.

Question, when the converstion hits a series or routers across the internet, they too must maintain that point to point connection right? Do you know, how this is done? Must have something to do with multiplexing whereby each converstation is muxed into existing channels...

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riturajborpujari profile image
Rituraj Borpujari

Yes. Routers use multiplexing to handle multi connections.
For eg wifi standards 802.11a/g/n uses Orthogonal Frequency Division Multiplexing, while the newer 802.11ac uses multiple antenna and Spatial Division Multiplexing along with OFDM to achieve greater speeds.