3.1 Basic Cable Types, Connectors, Features, and Purposes
COMPTIA A+ CORE 1 - DOMAIN 3
Cyber Wizard
This article provides an overview of common cable types, their connectors, features, and purposes, as required for the CompTIA A+ exam.
CompTIA A+ Exam Domain: Domain 3.1 - Explain basic cable types and their connectors, features, and purposes.
Network Cables
Networking cables connect devices in wired networks, using copper or fiber-optic transmission methods.
Copper Cables
Cat 5 – Supports up to 100 Mbps at 100 meters; outdated for modern networking.
Cat 5e – Enhanced version of Cat 5; supports up to 1 Gbps at 100 meters.
Cat 6 – Supports up to 10 Gbps at 55 meters; has better shielding to reduce crosstalk.
Cat 6a – Supports 10 Gbps at 100 meters with improved shielding.
Coaxial – Used for cable internet and TV; includes RG-6 and RG-59 types.
Shielded Twisted Pair (STP) – Reduces electromagnetic interference; used in high-noise environments.
Direct Burial – Specially designed for underground installations.
Unshielded Twisted Pair (UTP) – Most common in Ethernet networks; cost-effective but susceptible to interference.
Plenum vs. Non-Plenum
Plenum-rated cables – Designed with fire-resistant insulation for use in air-handling spaces.
Non-plenum (PVC) cables – Lower cost but not fire-resistant; used where fire codes permit.
Optical Fiber Cables
Fiber Optic – Uses light instead of electrical signals for high-speed, long-distance communication.
Single-mode fiber (SMF): Long-range, higher bandwidth.
Multi-mode fiber (MMF): Shorter-range, cost-effective.
T568A/T568B Wiring Standards
Defines the color-coded pinouts for RJ45 Ethernet connectors.
T568A – Common in government applications.
T568B – More commonly used in commercial networks.
Peripheral Cables
Peripheral cables connect external devices such as keyboards, mice, and printers.
USB 2.0 – 480 Mbps transfer speed; commonly used for peripherals.
USB 3.0 – Up to 5 Gbps; backward compatible with USB 2.0.
Serial – RS-232 standard; used for legacy devices and network equipment.
Thunderbolt – High-speed data and video transmission; supports up to 40 Gbps (Thunderbolt 3/4).
Video Cables
Video cables connect display devices such as monitors, projectors, and TVs.
HDMI (High-Definition Multimedia Interface) – Supports audio and video; commonly used in TVs and PCs.
DisplayPort – High-performance video and audio transmission; supports daisy-chaining multiple displays.
DVI (Digital Visual Interface) – Used in older monitors; available in DVI-D (digital) and DVI-I (integrated analog/digital) versions.
VGA (Video Graphics Array) – Analog video connection; becoming obsolete.
Hard Drive Cables
Hard drive cables connect storage devices to a computer’s motherboard.
SATA (Serial Advanced Technology Attachment) – Standard for modern internal hard drives.
SCSI (Small Computer System Interface) – Used in enterprise storage solutions.
eSATA (External SATA) – External version of SATA; allows direct connections to hard drives.
IDE (Integrated Drive Electronics) – Older parallel interface for hard drives.
Adapters
Adapters allow conversion between different cable and connector types. Examples include:
HDMI to VGA
USB-C to USB-A
DisplayPort to HDMI
RJ45 to USB (network adapters)
Connector Types
Different cables use specific connectors to ensure proper connectivity and compatibility.
RJ11 – Used for telephone lines.
RJ45 – Standard Ethernet connector.
F Type – Used in coaxial cable connections for TV and internet.
ST (Straight Tip) – Fiber optic connector, used in networking.
SC (Subscriber Connector) – Square fiber optic connector.
LC (Lucent Connector) – Small fiber optic connector for high-density applications.
Punchdown Block – Used for wiring network cables into patch panels.
microUSB – Small USB connector for mobile devices.
miniUSB – Older, slightly larger USB connector.
USB-C – Reversible USB connector with high-speed data and power delivery.
Molex – Power connector for older internal components.
Lightning Port – Apple’s proprietary connector for iPhones and iPads.
DB9 – 9-pin serial connector used for legacy communication devices.
Final Thoughts
Understanding cable types, connectors, and their uses is critical for troubleshooting, installation, and configuration in IT environments. The CompTIA A+ exam evaluates proficiency in identifying and working with various cables, ensuring IT professionals can effectively set up and maintain network, peripheral, and video connections.