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Day 21. Networking Fundamentals > Bluetooth - Pg. 85

Day 21 85 The Physical Layer of Ethernet All Ethernet cabling terminates with RJ-45 heads, uses a star/extended star topology, has a range of 100 meters (328 feet) per segment, has four twisted pairs of wires (but their usage varies), and all specs are defined by TIA/EIA. Table 21-3 shows the differences in Ethernet cabling. Table 21-3 Cabling 10BASE-T 100BASE-T 1000BASE-T Ethernet Cabling Comparison Speed 10 Mbps 100 Mbps 1000 Mbps Cable Category Rating 3, 4, or 5 (normally 5) 5, 5e, and 6 (normally 5) 5, 5e, and 6 (normally 5) Wires Used 2 pairs 2 pairs All 4 pairs The Physical Layer of WiFi The physical layer of WiFi might seem like a contradiction in terms. After all, the whole point of wireless is to avoid the physical connection. Still, WiFi has to move the physical data, in this case in the form of radio signals. All WiFi standards for the A+ exam are defined by IEEE 802.11. The four standards are A, B, G, and N. The A standard is only compatible with the N standard and has a very small range of 150 feet (45.7 meters). It is rare to find it today. The B and G standards are