Physical Media and Connectors
The physical media and the connectors used to connect devices into the media are defined by standards at the physical layer. The Ethernet and IEEE 802.3 (CSMA/CD) standards define a bus topology LAN that operates at a baseband signaling rate of 10 megabits per second (Mbps).
Learning about the different types of cables and connectors in an Ethernet LAN and their various functions can help you understand more about how a LAN works. Ethernet is the most widely used LAN technology. Since its initial implementation, Ethernet has been extended to four new types:
- 802.3u (Fast Ethernet)
- 802.3z (Gigabit Ethernet over Fiber)
- 802.3ab (Gigabit Ethernet over UTP)
- 802.3ae (10 Gigabit Ethernet)
- 10BASE2 – Known as Thinnet. Allows network segments up to 185 meters on coaxial cable by interconnecting or chaining devices together.
- 10BASE5 – Known as Thicknet. Allows network segments up to 500 meters on large coaxial cable with device tapping into the cable to receive signals.
- 10BASE-T – Carries Ethernet signals up to 100 meters on inexpensive twisted-pair wirring back to a centralized concentrator called a hub
The 10BASE5 and 10BASE2 standards provide access for multiple stations on the same segment by physically connecting each device to a common Ethernet segment. 10BASE5 cables attach to the bus using a cable and an Attachment Unit Interface (AUI). 10BASE2 networks chain devices together using coaxial cable and T connectors to connect the stations to the common bus.
Because the 10BASE-T standard provides access for a single station at a time, each station must attach to a common bus structure to interconnect all devices. The hub becomes the Ethernet devices’ bus and is analogous to the segment.