I'm thoroughly stumped and the Google isn't yielding the answer I seek.
Consider an Ethernet utp link, where both ends are configured as 10mbps half duplex. All the documentation I can find tells me the same thing: csma-cd is used in half-duplex configurations of Ethernet utp to allow a shared medium to be utilized by multiple devices by providing rules to mitigate collisions. I would consider a shared medium in this case to be one twisted pair.
My issue is: how many pairs of wire are actually used for such a config. My logical brain tells me that one pair is needed, and would qualify as a shared medium just as a coax 10base-2 lan would be. The problem is hat I cannot find any documentation which specifies this. I find plenty that tell me two pairs are required for any utp Ethernet link of 10 or 100mbps of the most common types. It's almost like the half duplex part is an afterthought.
Can anyone shed some light on what's really going on in a 10mbps utp half duplex physical link?
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