Connectors and Wiring Standards

Physical Transmission Media

Transmission media is the physical path a signal travels between devices. Three types dominate modern networking: coaxial cable, twisted-pair cable, and fiber-optic cable. Each trades off speed, distance, cost, and noise resistance differently — which is exactly what the rest of this chapter breaks down.

Exam angleAlmost every wiring question on the exam is really asking you to weigh these four tradeoffs against each other: speed, distance, cost, noise immunity.

Coaxial Cable

Coax is built from a central copper conductor, a dielectric insulator, a metallic braided shield, and an outer jacket. That braided shield is what protects the signal from EMI and RFI.

Twisted-Pair Cable

Pairs of insulated copper wires, twisted together specifically to cancel out crosstalk and EMI. UTP (Unshielded Twisted Pair) is the standard for LAN installations; STP (Shielded Twisted Pair) adds shielding for noisier environments.

Naming conventionEthernet designations follow the pattern N-Signaling-X. Take 100BaseTX: 100 = 100 Mbps, Base = baseband signaling, T = twisted pair.

Cable Categories

Twisted-pair cable is rated by category. Click a row to see the exam-relevant detail for that rating.

Click a category above for details.

Exam angleCat 6A is the minimum category the exam expects for 10 Gbps at the full 100-meter run.

Twinaxial & Direct Attach Copper

Twinaxial cable (twinax) handles short-distance, high-speed links inside data centers. Direct Attach Copper (DAC) cables are fixed-length twinax runs with connectors already built onto both ends — cheaper than fiber and a good fit for anything under 10 meters.

Fiber-Optic Cable

Fiber sends data as pulses of light instead of electrical signals, which is why it is completely immune to EMI and RFI.

Advantages

Long distance — up to 40–80 km for single-mode
Immune to electrical interference
High bandwidth

Disadvantages

Higher installation cost
Fragile core
Specialized testing tools required

Single-Mode vs. Multimode Fiber

Flip each card for the detail the exam actually tests.

Fiber Connectors & Polish Types

Five connector styles show up repeatedly on the exam. Explore each one below, then check the polish type that goes with it.

APC — green

Angled polish. Lower return loss, so less light reflects back toward the source. Connector body color-coded green.

UPC — blue

Flat (ultra) polish. Standard performance, connector body color-coded blue. Never mix APC and UPC connectors in the same link.

Transceivers

A transceiver combines a transmitter and receiver in a single module. Click a type to see how its speed compares.

Media Converters & Serial Connections

Two supporting technologies worth knowing cold for the exam.

Cable Properties

Four properties define how well a cable performs, no matter the type.

Noise immunity, ranked

Duplex

Half-duplex: send or receive, never both at once.
Full-duplex: send and receive simultaneously.

Distance & Attenuation

UTP tops out at 100 meters (328 ft). Attenuation is the signal degrading the farther it travels — the reason every cable type has a maximum run length.

Wiring Standards — T568A & T568B

T568A and T568B are pinout standards for terminating twisted-pair cable. The only difference between them: the orange and green pairs are swapped. Toggle below to see it.

RuleA→A or B→B on both ends = straight-through. A on one end, B on the other = crossover.

Try it — what cable does this make?

Ethernet Cable Types

Three cable wiring patterns, three distinct jobs.

Straight-Through

Host to switch. Router to switch.

Crossover

Switch to switch. Host to host.

Rolled (Rollover)

Console connection into a router or switch.

Distribution Infrastructure

The physical backbone of structured cabling. Flip each card.

Exam Check

Six quick questions pulled straight from this chapter.

Score: 0 / 0

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