On Mon, 2012-05-21 at 13:38 +0100, Brian Smith wrote: > With a phone line, or indeed a TV aerial, you can just plug in a > splitter and it shares the line. This is obviously not possible with a > network. Am I right that this is because each connected device needs > its own IP address (and will already have its ownMAC address)
it's lower level than that, an ethernet cable has 4 twisted pairs carrying the signals (not all are used in every transmission standard) with 100M ethernet one pair goes from the Tx of one end to the Rx of the other, and another pair does the opposite. There are two spare pairs, the most obvious being the one on the central pins which can be used to carry a phone signal on the same socket as a network. http://www.ertyu.org/steven_nikkel/ethernetcables.html may help. In case you have some surprises lurking in your walls ;-) A TV aerial is like a bit of the atmosphere carrying radio frequency signals trapped in a pipe, so a number of things can listen in parallel - bit like the old style coax ethernet cable. A phone line has one pair carrying the signal, and again you can connect more than one device in parallel across it at once. Phil _______________________________________________ Peterboro mailing list Peterboro@mailman.lug.org.uk https://mailman.lug.org.uk/mailman/listinfo/peterboro
