My telephone wiring is actually cat5E cabling. I discovered that 2 pairs are needed for networking PCs. The remaining two pairs can be used for telephones. The nice thing is that they converge together and reach into each room.

If you are interested in a small narrative and photos, PM me with your email address and I will send you a detailed description and photos.

I find it really convenient having a network jack coupled to each phone jack.

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R7.3: 0.22.20091023-1, Hauppauge PVR-500 (Philips FQ1236A MK4), Gigabyte Gigabyte EG45M-UD2H, E5200 2.4Ghz, 2GB RAM, NVIDIA GEFORCE 256MB

does gigabit utilize more copper lines?

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R5F1 - Dell P4 2.4Ghz 500MB - PVR250 x 2 - GeForce FX 5200 - Onboard sound/NIC 80GB ATA/250GB ATA/400GB SATA

Gigabit ethernet devices generally need Cat5e or Cat6 to run at speed, and I think it wants all the pairs connected through because it's comparing levels across them, my memory says that one of each twisted pair is the ground/shield wire and the other one is the actually signal wire, and it's doing differential something between the signal wires of two pairs for each circuit. (thus 8 wires, in 4 pairs, one xmit quad, and one rcv quad) I forget the exact terminology but one of our EEs can pipe up.

The differential thing is a noise rejection trick. Any induced voltage levels in the cable should be close to the same for all the pairs so by driving two pairs in opposite directions (+/-) and comparing between them you get a really robust signal.

I did this myself a couple years back. Works great. Good tip.

For Fast ethernet (100Mb/s) it uses two unidirectional 100Mb/s links, using a total of 4 pairs of wires.

Gigabit uses four bidirectional 250Mb/s links, so yes, it needs all four pairs in the Cat5/5e/6 cable.

Also, cable quality is related to distance and speed, so you may well be able to run gigabit over short runs of cat5 without problems (I have) but over longer distances you'll start to get errors.

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Mephi
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R5.5
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