cat 5 wiring: Category 5 cable is eight-wire twisted pair meeting a number of specs. IBM spent a billion dollars to determine how to get the maximum throughput and error control characteristics from copper wire over long distances, and what they came up with is cat-5. [thanks Ian and Iris] Good for up to at least 100 Mbps.
Null Modem cable: An RS-232 serial cable with the send & recieve signal wires (and some other wires when used) crossed. When used to connect two computers by their serial ports, it acts somewhat like the "normal" setup of serial-cable::modem:: telephone system::modem::serial-cable.
Patch cable: In networking jargon, this is a 10BASE-T cable with the signal wires crossed as in a null-modem cable. Used to make a two computer network without the expense of using a "hub".
10BASE-2: Thin Ethernet. Roughly quarter-inch, 50 ohm (?), coaxial cable, usually black. Requires use of BNC connectors and "terminators" (BNC connectors with terminating resistors or "active termination" (a small transisterized circuit)).
10BASE-T: Usually UTP (Unshielded Twisted Pair). For example: Category 5 cable. Can be STP (Shielded Twisted Pair). Category 5, 4, 3, and 2 cable is good for 10 Mbps, Cat 5 for 100 Mbps. Usually with 8-contact RJ-45 connector.
FDDI: Fiber something something Interface. Fiber optics cables.
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