Fundamentals of Ethernet LAN Flashcards
Ethernet
Family of LAN standards with standard names that begin with 802.3 that together define the physical and data-link layers of the world’s most popular WIRED LAN technology
Wireless LANs
Defined by the IEEE using standards that begin with 802.11, use radio waves to send the bits from one node to the next
Unshielded Twisted Pair (UTP)
Transmits data over electrical circuits via the copper wires inside the cable.
Suffix includes T (Twisted pairs)
Up to 100 meters
Fiber-optic
Sends light over glass fibers in the center of the cable.
Although more expensive, optical cables typically allow longer cabling distances between nodes.
Suffix includes X
Ethernet header and trailer
Bytes of overhead data that Ethernet uses to do its job of sending data over a LAN, with the same format no matter the speed or the medium
Ethernet Frame
Refers to the header and trailer of a data-link protocol, plus the data encapsulated inside that header and trailer
10BASE-T
Standard Ethernet 10Mbps
2 pairs of wires
100BASE-T
Fast Ethernet (FE) 100Mbps 2 pairs of wires
1000BASE-T
Gigabit Ethernet (GE)
1000Mbps
4 pairs of wires
Electro Magnetic Interference (EMI)
When electrical current passes over any wire, it creates electromagnetic interference that interferes with the electrical signals in nearby wires, including the wires in the same cable.
Crosstalk
Electro Magnetic Interference (EMI) between wire pairs in the same cable
Ethernet link
Any physical cable between two Ethernet nodes
Network Interface Card (NIC)
Standard name for PC network Card
Gigabit Ethernet Interface Converter (GBIC)
The original form factor for a removable transceiver for Gigabit interfaces
Small Form Pluggable (SFP)
The replacement for GBICs, used on Gigabit interfaces, with a smaller size, taking less space on the side of the networking card or switch
Small Form Pluggable Plus (SFP+)
Same size as the SFP, but used on 10-Gbps interfaces.
10BASE-T and 100BASE-T Straight-Through Cable Pinout
For transmission, pin 1 and 2 on one end of the cable to pin 1 and 2 at the other end of the cable
For receiving, pin 3 and 6 on one end of the cable to pin 3 and 6 at the other end of the cable
10BASE-T and 100BASE-T Crossover Cable Pinout
Pin 1 and 2 on one end of the cable to pin 3 and 6 at the other end of the cable, and viceversa
Straight-through vs Crossover cable
Straight-through cable, if the endpoints transmit on different pin pairs
Crossover cable, if the endpoints transmit on the same pin pairs
Devices which transmit on Pins 1,2
PC NICs
Routers
Wireless access point (Ethernet interface)