When we think about what CSMA really does; we have to ask this question. In an Ethernet environment with only 1 NIC card, is "Full Duplex" mode really able to send and receive at the same time?

My original thought was no, until I was reminded by @riturajborpujari below that NIC cards can operate in full duplex mode. He reminded me of crossover cables, which establish two point to point connections. In this mode CSMA is turned off.

Is there such a thing as Full Duplex in an Ethernet Environment? Yes

• CrossOver cables are true duplex
• Any network with switches (which work at Mac layer) establish 'logical' point to point connections
• Routers can use both switches and or a technique named Mutipexing (Muxing)

Interesting Links:

Ever wondered about the maximum throughput of GigaBit Ehternet

Bandwidths for all known devices

Did you know, that telephone companies were charging around $2,000.00 per month for T1 service throughout the 90's? At 1.5Mb/s that's equivalent to your wireless router @ 2Mb/s for a one time fee of $99.00 (for a good one) which may last 10 years.

DS1 / T1 (and ISDN Primary Rate Interface)  1.544 Mbit/s    1990