Unit 4
Chapter 2
Cable
Ethernet Coaxial
Thicknet (500 meters)
RG-8 – 10Base5
MAU or MSAU
Vampire Tap
50 ohm terminating resisters at every endpoint
Thinnet (200 yards, 185 meters)
RG-58 – 10Base2
Connectors: BNC (“bayonet”) – a steel, stick and twist connector
50 ohm resisters
Cable Service Coaxial/Twinaxial
RG-6 – Cable TV service, analog service, security cameras
RG-62 – TV
RG-59 – Cable service : Siamese (TwinAxial) cable: coax bonded to two conductor wires (primitive “power over ethernet” – analog)
75 ohm resisters
Twisted Pair Ethernet
Twisted pair Ethernet cable has 4 pairs (8 wires), but only 2 pairs are used. Theoretically this supports 2 Ethernet ports per cable, though this feature usually goes unused. Ports and jacks use the RJ-45 standard, similar to the telephone RJ-11 jack.
Get familiar with the T-568A & B jack and plug pinout configuration. Memorize the B pinouts and learn to use the acronym GO to get the A pinouts. For some reason everyone uses B most of the time. This site is clear and to-the-point:
https://incentre.net/ethernet-cable-color-coding-diagram/
Almost all standards for Twisted Pair call for runs of a maximum of 100 meters. In-wall cable is usually limited to 90 meters to allow patch cables at both ends.
STP
Shielded Twisted Pair
Was mostly used with Token Ring.
Use in high-EMI/RFI areas where shielding is needed.
UTP
Unshielded Twisted Pair
10BaseT: minimum Cat 3
100BaseTX, which became simply
100BaseT: minimum Cat 5
100BaseT4: an early alternative that used all 4 pairs in a Cat 3 cable
1000BaseT or 1GBaseT: Cat5e
10GBaseT: Cat 6 will get you 55 meters, Cat 6a will get you 100 meters.
Fiber Optic
LEDs – short distance
Lasers – long distance
Multimode fiber: usually orange; short distance; uses multiplexing, for instance three different signals: red, green and blue
Single-mode fiber: usually yellow; long distance; simplex: only one signal stream
Physical Contact (PC) Connectors
Flat-surface connector
Ultra Physical Contact (UPC)
Angled Physical Contact (APC)
Media converters
10BaseFL – early fiber optic
100BaseFX
1000BaseSX: “S for short” distance, up to 500 meters
1000BaseLX: “L for long” distance, up to 5 kilometers
ATM over SONET rings
The national long-distance telephone system.
10 Gbps
ATM used 53 byte cells
Fading away…
Metro Ethernet over SONET
Uses SONET rings, so 10GB
10GBaseSR: S for short; R is for eth-R-net; multimode; 300 meters
10GBaseSW: W is for WAN (meaning ATM signaling, not Ethernet); multimode; 300 meters
10GBaseLR: Ethernet, single-mode; 10 kilometers
10GBaseLW: WAN/ATM; 10 km
10GBaseER: E is for extra-long; ethernet; 40 km
10GBaseEW: WAN/ATM; 40 km
Connectors
ST – Stick and Twist
SC – Stick and Click
LC – the “Little Connector” (actually Lucent)
Early Gigabit Media
1000BaseCX (copper, 25 yd)
1000BaseSX (“short” fiber-optic)
1000BaseLX (“long” fiber-optic)
Boxes
Repeater – Layer 1 – usually for coaxial, but there are twisted pair repeaters too.
Bridge – Layer 2 – also usually for coax, and essentially a 2-port switch, i.e. it keeps a MAC table.
Hub – Layer 1 – has no MAC filtering.
Switch – Layer 2 – isolates traffic based on MAC addresses.
Router – Layer 3 – routes internet traffic based on IP addresses. This is the only Layer 3 box in this list.
Transceivers
MSA
SFP+