Comptia a+ 3.1
General Networking Cable Concepts
Q: What are the two main types of network cables?
A: Copper cables and fiber optic cables.
Q: What is the purpose of a network cable?
A: To connect devices in a network and allow data transmission.
Copper Cables - UTP/STP
Q: What does UTP stand for?
A: Unshielded Twisted Pair
Q: What is the purpose of twisting wires in a UTP cable?
A: To reduce electromagnetic interference (EMI) and crosstalk.
Q: What is the maximum segment length for UTP cables?
A: 100 meters (328 feet)
Q: What does STP stand for?
A: Shielded Twisted Pair
Q: What is the main advantage of STP over UTP?
A: Better protection against EMI.
Q: Name two types of shielding used in STP cables.
A: Overall foil shield (F/UTP) and Shielded Foiled Twisted Pair (S/FTP).
Q: Where is STP cable commonly used?
A: Data centers and industrial settings.
Copper Cable Categories
Q: What does the "Cat" rating of a cable indicate?
A: The cable's performance specifications (speed and bandwidth).
Q: What is the maximum speed of Cat 5 cable? Is it commonly used today?
A: 100 Mbps. No, it's obsolete.
Q: What is the maximum speed of Cat 5e cable?
A: 1 Gbps (Gigabit Ethernet).
Q: What are the two speeds supported by Cat 6 cable and at what distances?
A: 1 Gbps at 100 meters and 10 Gbps at 55 meters.
Q: What is the maximum speed and distance of Cat 6a cable?
A: 10 Gbps at 100 meters.
Q: Which cable type is ideal for high-speed networks and backbone cabling?
A: Cat 6a
Specialized Copper Cables
Q: What are plenum-rated cables, and where are they used?
A: Cables with fire-retardant materials, used in plenum spaces (air circulation areas).
Q: How are plenum-rated cables identified?
A: They are marked as CMP (Communications Plenum).
Q: What are direct burial cables?
A: Cables designed for installation underground without conduit.
Q: What features make direct burial cables suitable for outdoor use?
A: Resistance to moisture, temperature changes, and physical damage; often gel-filled or armored.
Copper Cabling Connectors
Q: What type of connector is commonly used with Ethernet cables?
A: RJ45 connector.
Q: What does RJ45 stand for (in terms of positions and contacts)?
A: 8-position, 8-contact (8P8C).
Q: What are the two wiring standards for RJ45 connectors?
A: T568A and T568B.
Q: When would you use a straight-through cable vs. a crossover cable (in terms of T568 standards)?
A: Straight-through: Same standard on both ends. Crossover: T568A on one end and T568B on the other.
Q: What is an RJ11 connector commonly used for?
A: Telephone wiring and DSL connections.
Copper Cabling Installation Tools
Q: What tool is used to remove the outer jacket of a cable?
A: Cable stripper.
Q: What tool is used to cut and trim wires?
A: Snips (electrician's scissors).
Q: What is the purpose of a punchdown tool?
A: To insert wires into insulation-displacement connectors (IDCs) on patch panels or keystone jacks.
Q: What tool is used to attach RJ45 connectors to cables?
A: Crimper.
Copper Cabling Testing Tools
Q: What type of tool is used to verify electrical connections in a cable?
A: Cable tester.
Q: How does a toner probe help with cable identification?
A: It sends a signal through the cable (tone generator) and detects it along the route (probe).
Q: What is the purpose of a loopback plug?
A: To test the transmit and receive functions of network ports.
Fiber Optic Cables
Q: How do fiber optic cables transmit data?
A: Using light signals.
Q: What are the main components of a fiber optic cable?
A: Core, cladding, buffer coating, and jacket.
Q: What is the difference between single-mode fiber (SMF) and multi-mode fiber (MMF) in terms of core size and light source?
A: SMF: Smaller core, laser light source. MMF: Larger core, LED or VCSEL light source.
Q: Which type of fiber is used for long-distance communication?
A: Single-mode fiber (SMF).
Q: Which type of fiber is commonly used in LANs and data centers?
A: Multi-mode fiber (MMF).
Q: Name three common types of fiber optic connectors.
A: ST (Straight Tip), SC (Subscriber Connector), LC (Lucent Connector).
Coaxial Cables
Q: What are coaxial cables primarily used for?
A: Television signals (CATV), broadband internet (cable modems), and security cameras (CCTV).
Q: What are the main components of a coaxial cable?
A: Inner conductor, dielectric insulator, shielding, and outer jacket.
Q: What type of connector is commonly used with coaxial cables for TV and internet?
A: F-Type Connector.
Network Taps and Monitoring
Q: What is the function of a network tap?
A: To provide a way to monitor network traffic for analysis.
Q: What is the difference between a passive tap and an active tap?
A: Passive tap: Physically splits the signal. Active tap: Powered device that regenerates signals.