Twister Pair and Connector Flashcards
How many wires are in twisted pair cabling, and how are they arranged?
8 wires (4 pairs); each pair carries positive and negative signals and is twisted to reduce EMI and crosstalk.
What is the purpose of twisting the wire pairs?
To reduce EMI and crosstalk.
What’s the difference between UTP and STP?
UTP has only an outer sheath; STP includes a grounded copper shield for added EMI protection
What are T568A and T568B?
Wiring standards that define the wire order for RJ45 connectors.
What are the advantages of twisted pair cabling?
Inexpensive, easy to install, flexible, lightweight, widely supported.
What are the disadvantages of twisted pair cabling?
Susceptible to interference, cable damage, eavesdropping; low bandwidth.
What connector does a phone cable use, and what speed does it support?
RJ11; 10 Mbps.
What is the speed and frequency of Cat 5 and Cat 5e cables?
100 Mbps (Cat 5) and 1000 Mbps (Cat 5e); both at 100 MHz.
Which category supports 10 Gbps up to 55 meters?
Cat 6 (250 MHz).
What’s the difference between Cat 6 and Cat 6a?
Cat 6a supports 10 Gbps up to 100 meters and has better shielding and tighter twists.
Which cable categories are shielded-only and support 10+ Gbps?
Cat 7, 7a, 8.1, 8.2.
What speeds and frequencies do Cat 8.1 and 8.2 support?
Cat 8.1: 25 Gbps @ 2000 MHz; Cat 8.2: 40 Gbps @ 2000 MHz.
When should you use solid core vs stranded core UTP cable?
Solid for long runs (in walls/ceilings); stranded for flexible, moveable cables.
Can a higher category cable replace a lower one?
Yes, but not vice versa. (e.g., Cat 6 can replace Cat 5e, but not the other way around.)
What is direct burial cable?
Cable designed to go directly in the ground with no added protection.
What is plenum-rated cable used for?
Areas with air circulation like ceilings/floors. It’s low-toxicity and flame-retardant.
What does riser-rated cable do?
Runs between building floors, tested for vertical flame spread (UL-1666).
What’s the downside of general-purpose cable?
High toxicity and corrosive gases when burned.
What are RJ11 connectors used for?
Phone lines; support up to 2 wire pairs.
How many pins does an RJ45 connector have, and what is it used for?
8 pins; used for Ethernet networking.
What’s the difference between patch and crossover cables?
Patch cables use the same standard on both ends (T568A or T568B); crossover uses T568A on one end and T568B on the other
What are the wire colors in T568A order (Pins 1–8)?
GW, G, OW, B, BW, O, BrW, Br.
What are the wire colors in T568B order (Pins 1–8)?
OW, O, GW, B, BW, G, BrW, Br.
Which pins are used for Tx and Rx in 100BASE-T?
1 (Tx+), 2 (Tx-), 3 (Rx+), 6 (Rx-).
