Network Cables and Connectors Flashcards
Cat 1 - Class A - 100 kHz - Description?
Low speed cable used for older voice telephone installations. Not for use in data networks.
Cat 2 - Class A - 1 MHz - Description?
Used in older data networks like ARCnet and early Token Ring.
Cat 3 - Class A - 16 MHz - Description?
Used in early Ethernet; unsuitable for faster networks, but still used for voice telephone cables.
Cat 4 - Class A - 20 MHz - Description?
Used by early Ethernet and some Token Ring networks, but was never common.
Cat 5 - Class A - 100 MHz - Description?
Widely used for Fast Ethernet and Gigabit Ethernet networks, also used for telephone and video. Superseded by Cat5e.
Cat 5e - Class A - 100 MHz - Description?
Category 5 Enhanced. Same overall properties as Cat5, but higher testing standards.
Cat 6 - Class A - 250 MHz - Description?
Stronger crosstalk specifications than Cat 5e. Popular for new Gigabit Ethernet installations, and short distance 10 Gigabit Ethernet networks. Frequently shielded for additional EMI protection; if so, the shielding needs a grounded connection.
Cat 6a - Class A - 500 MHz - Description?
Augmented Category 6. Shielded, and allows full distance 10 Gigabit Ethernet operation.
Cat 7 - Class A - 600 MHz - Description?
Similar to Cat6A, but screened and shielded for higher noise resistance.
Cat 7a - Class A - 1000 MHz - Description?
Augmented Category 7. May be suitable for emerging 40 Gigabit Ethernet.
10BASE-T
The first popular twisted-pair Ethernet standard, used in the early 1990s. Operates at 10 Mbps, using two wire pairs on a Cat3 or higher cable.
100BASE-TX
A 100 Mbps standard, also known as Fast Ethernet. It still uses two wire pairs, but requires Cat5 or higher cable.
1000BASE-T
Also known as Gigabit Ethernet, since it operates at 1000Mbps.
10GBASE-T
As the name implies, 10 Gigabit Ethernet operates at 10 Gbps, using all four pairs of Cat6a cable.
How does the pitch of a twisted pair affect crosstalk?
In general a higher pitch provides more protection. Parallel pairs, like those in the same cable, should use a slightly different pitch from each other so their twists don’t line up.
What’s special about plenum-grade cable?
It uses fire-retardant insulating materials that won’t produce toxic smoke, so it’s safe for use in a ventilation system.
You’re replacing all the wiring in your office. What twisted-pair standards would you consider, balancing performance and cost?
Answers may vary. Cat3 cable today should only be used for voice telephone lines. Cat5e is the cheapest option suitable for high speed networks, but Cat6 supports faster standards. For 10 Gigabit Ethernet over long distances, you need Cat6a.
What’s the fastest Ethernet standard supported by your NIC?
Answers may vary, but most new PCs support 1000BASE-T
Name the colour order for a T-568A Cable
Green Stripe, Green, Orange Stripe, Blue, Blue Stripe, Orange, Brown Stripe, Brown
Name the colour order for a T-568B Cable
Orange Stripe, Orange, Green Stripe, Blue, Blue Stripe, Green, Brown Stripe, Brown
Termination tool - Snips
Cuts cables to length.
Termination tool - Wire stripper
Cuts the jacket from the cable.
Termination tool - Crimper
Clamps a modular jack onto the wire ends of a cable.
Termination tool - Punch down tool
Places wires on punch down blocks. It uses a spring-loaded blade to push the wire in place, pierce the insulation, and cut excess length in a single motion.
What’s the difference between RJ-11 and RJ-45 connectors?
RJ-11 is a smaller 6-position connector used for analog telephones, while RJ-45 is a larger 8-position connector used primarily for Ethernet.
When should you use the T568A wiring standard, and when should you use T568B?
Both have identical performance, but you want to pick one or the other for the entire network, and especially when wiring any particular cable. One exception is if you’re making a crossover cable: one end should be T568A, and the other end should be T568B.
If time and equipment allow, terminate an Ethernet cable.
A. Using snips, cut the cable to length.
B. Using a wire stripper, remove the last 1 1/2” of outer cable jacket.
C. Spread the four pairs out, then unwind 1/2” of each one.
D. Line the wires up in T568A order, then trim them evenly. If your organization uses T568B instead, you can also use that
E. Slide the wires into the RJ-45 connector.
F. Insert the connector into the crimper die, then clamp down until you hear a click.
Multimeter
A general-purpose electronic tester which can measure resistance, current, or voltage between two points.
Toner probe
A connectivity-testing tool that can be used to trace and identify a wire along its entire length.
Cable tester
A cable testing tool that at the minimum measures conductivity and resistance to detect breaks and shorts. Different variants might be known as line testers. Some cable testers are more sophisticated and can measure cable length, check for noise levels, or detect what device is on the other end of an active cable.
Time-domain reflectometer
A more sophisticated cable tester. Measures signal reflections along a cable to find breaks, shorts, or even minor flaws along its path, and estimate their locations.
Cable certifier
A device that can perform advanced tests on cable quality and certify that it meets appropriate performance standards.
Loopback plug
Connects transmit and receive pins on a connector, effectively letting it plug into itself to allow diagnostic tests.
What tool can measure resistance, current, and voltage between two points?
Multimeter
What connector can be used with the twisted-pair cable?
RJ-45
What tool measures signal reflection along a cable to find break and estimate their locations?
Time-domain reflectometer
twisted-pair cable - It uses a balanced pair that is a circuit made of two identical wires around itself for the length of the cable.
True
twisted-pair cable - It is similar to coaxial cable and serves as a pipe-like waveguide for electromagnetic signals.
False
twisted-pair cable - It can reduce crosstalk when the pairs are very close together such as multiple sets within a single cable.
True
twisted-pair cable - It is used to transmit light waves, usually it is near-infrared which is a bit lower frequency than visible light.
False
twisted-pair cable - It has four pairs for a total of eight conductors depending on the standard all might be used for data.
True
RG standard - RG-59
Common for baseband video and older cable television systems. Not reliable for broadband network connections.
RG standard - RG-6
Standard for newer digital cable, satellite, and cable modem connections. Essentially a higher grade RG-59.
RG standard - RG-11
Used for the same purposes as RG-6, but usually only for long distance drops and underground cables.
RG standard - RG-8
Used by 10BASE5 “Thicknet” Ethernet, the first Ethernet standard. Now obsolete.
RG standard - RG-58
Used by 10BASE2 “Thinnet” Ethernet, a cheaper but more limited alternative to Thicknet. Also obsolete.
What RG standard is used by 10BASE2 Ethernet?
RG-58
The BNC connector is a miniature quick connect/disconnect radio frequency connector used for coaxial cable. True or False?
True
The RG-59 standard is common for baseband video and older cable television systems. True or False?
True
Optical fiber - Core
The transparent fiber that carries the signal.
Optical fiber - Cladding
A second layer immediately surrounding the core.
Optical fiber - Buffer
Strengthens and protects the fiber itself, but doesn’t affect its optical properties.
Optical fiber - Strength members
Provides tensile strength to support the cable and reduce physical stress on the glass fibers.
Optical fiber - Outer jacket
The outermost layer of the cable, usually colour coded to give technicians information about the type of fiber inside.
Fiber type - Optical cable
oesn’t need EMI shielding. However, cables for outdoor use need more physical protection than those used indoors; cables for underground or underwater installation still more.
Fiber type - Plenum-grade
use materials that don’t easily burn or produce toxic smoke.
Fiber type - Multifiber cable
have more than one optical fiber in a single jacket. Each fiber is optically independent from the others, so can be used for separate channels or duplex operation.
Connector standard - ST (Straight Tip)
Size = 2.5 mm round Coupling = Bayonet Notes = One of the first popular MMF connectors, but less common for SMF. Increasingly being replaced by small form factor (SFF) connectors.
Connector standard - FC (Ferrule Connector or Fibre Channel)
Size = 2.5 mm round Coupling = Screw Notes = An early single-mode connector using the same ferrule type as ST. Very popular in the past, now being replaced by SC and LC connectors.
Connector standard - SC (Subscriber connector, or standard connector)
Size = 2.5 mm round Coupling = Push/pull snap Notes = Square bodied and using the same standard ferrule; commonly two are clipped together in a duplex SC-DC format.
Connector standard - LC (Lucent connector, or local connector)
Size = 1.25 mm round Coupling = Snap Notes = A SFF connector. Similar appearance to SC, but smaller and with a retaining clip. Available in single and duplex formats.
Connector standard - MT-RJ (Mechanical Transfer - Registered Jack)
Size = 2.45 mm x 4.4 mm rectangle Coupling = Snap Notes = A duplex SFF connector. Looks very much like an RJ-45 connector, and has two fibers in a single rectangular ferrule.
Optical Media Problem - Attenuation
Impact - Noise
Description - Cable too long, or cable flaws decreasing transparency.
Solution - Replace cable, use shorter cable, or insert repeaters.
Optical Media Problem - Bad cable or connector
Impact - Noise or no signal
Description - Flawed or damaged cable or connector.
Solution - Replace defective components.
Optical Media Problem - Dirty connector
Impact - Noise
Description - Connector ends must be kept very clean.
Solution - Clean and polish connectors, then reconnect.
Optical Media Problem - Bend radius limitation
Impact - Noise
Description - Tight bend or kinks can cause temporary or permanent damage
Solution - Straighten tight bends. Replace damaged cables.
Optical Media Problem - Mismatched connection
Impact - Noise or no signal
Description - Wrong connector type or shape.
Solution - Replace connector or module.
Optical Media Problem - Mismatched wavelength
Impact - No signal
Description - Wrong optical signal.
Solution - Replace incompatible optics.
Optical Media Problem - Mismatched fibre type
Impact - No signal
Description - MMF/SMF, or wrong fiber grade.
Solution - Replace incompatible cable.
Optical Media Problem - Network hardware failure
Impact - No signal
Description - Defective transceiver or power failure.
Solution - Diagnose or replace the affected device.
What fibre-optic cable connector uses a push-pull latching mechanism similar to common audio and video cables?
SC - Subscriber connector, or standard connector
The ST connector is a fibre-optic cable connector that uses a bayonet plug and socket.
True
What connector looks very much like an RJ-45 connector and has two fibres in a single rectangular ferrule?
MT-RJ
Optical Cable Part - Buffer
Strengthens and protects the fibre itself but does not affect its optical properties
Optical Cable Part - Outer Jacket
The layer of the cable which is usually colour coded to give technicians the information about the type of fibre inside
Optical Cable Part - Cladding
The transparent fibre that carries the signal
Optical Cable Part - Core
A second layer, immediately surrounding the first layer, which is also transparent but has a different refractive index
Optical Cable Part - Strength Members
Provide tensile strength to support the cable and reduces physical stress on the glass fibres
Cable Certifier
A device that performs advanced tests on cable quality and certifies that it meets appropriate performance standards.
Coaxial Cable
A cable that has a core wire surrounded by a conducting shield.
Ferrule
A rigid cylinder that fits over the end of the cable.
Fibre Coupler
A type of splitter where multiple fibres on one end are fused to join at a single core.
Multimeter
A general-purpose electronic tester which measures resistance, current, or voltage between two points.
Outer jacket
The outermost layer of the cable, usually colour coded to give technicians information about the type of fibre inside.
Patch Panel
A device housing a row of modular jacks in front, and a corresponding punch down block in rear.
Toner Probe
A connectivity-testing tool that can be used to trace and identify a wire along its entire length.
