2 – Infrastructure Flashcards
What is UTP?
Unshielded Twisted Pair • The most common type of copper cabling
In the context of cables, what is STP?
Shielded Twisted Pair • Provides additional shielding to protect against interference. • Requires the cable to be grounded, so a grounding wire is added to the groups of twisted pairs.
What is the standard and distance supported by this cable category? Cat 3
10BASE-T (10 Mb) 100 meters
What is the standard and distance supported by this cable category? Cat 5
100 Mb or 1000 Mb (100BASE-TX, 1000BASE-T) 100 meters
What is the standard and distance supported by this cable category? Cat 5e
100BASE-TX, 1000BASE-T (100 Mb or 1000 Mb) 100 meters
What is the standard and distance supported by this cable category? Cat 6
10GBASE-T 37-55 meters
What is the standard and distance supported by this cable category? Cat 6A
10GBASE-T 100 meters
What is the standard and distance supported by this cable category? Cat 7
10GBASE-T 100 meters
What is plenum-rated cable?
Meant for running through a plenum (a ceiling where airspace is circulating, which has fire-safety requirements). Typically not as flexible as regular PVC cable.
What types of Coaxial cables are there?
RG-6 • used in TV, digital cable, and high-speed internet over cable RG-59 • used as patch cables, not for long distances
What types of connectors are used with Coaxial cable?
BNC • Bayonet Neill-Concelman • Connector that you push in and twist to lock in place. • Often used in DS3 WAN links F-Connector • Often used with cable television / cable modem • Threaded connector, screws into place
What is a DB-25?
D-subminiature, or D-sub • “D” indicates shape of connector, B indicates size • 25 pins • DB-25 was one of the most popular serial connector types early on in computing. Not seen much today. • Often-color coded pink. • used for all kinds of different things: printing, modems, mice, networking.
What is a DB-9?
D-sub 9 • “D” indicates shape of connector, B indicates size • Technically, it’s properly a DE-9, since it is a size E D-sub rather than size B. • 9 pins • Can be color-coded green/teal. • Still seen today, often as a serial console interface for infrastructure devices
Single-mode vs. multimode fiber
Multimode • for short range, up to 2 km • uses an inexpensive light source, ex. LED • wider core, light disperses into multiple modes Single-mode • long range, up to 100 km • expensive light source; laser beams • narrow core, allows single mode of light
UPC vs. APC
UPC • Ultra-polished connector (or, Ultra-physical contact connector) • Ferrule end-face radius polished at 0 degree angle • high return loss (signal reflects back directly) APC • Angle-polished connector (or, Angled-physical contact connector) • Ferrule end-face radius polished at an 8 degree angle • Lower return loss (signal reflects back at angle, instead of back to source) • Higher insertion loss
What is an ST?
Straight Tip • Fiber connector • Round bayonet, push and twist to lock • long ferrule sticks out
What is an SC?
Subscriber Connector, or Standard Connector, or Square Connector • square shaped • round ferrule, but does not stick out as much as an ST conenctor • pushes into place, no lock
What is an LC?
Lucent Connector • aka Local Connector • “Little Connector” • smaller than SC, square shape, round ferrule that does not stick out much • locks into place with a tab like an RJ45
What is an MT-RJ?
Mechanical Transfer Registered Jack • smallest form of fiber connector • TX and RX fibers in the same form factor • Roughly same size as RJ45
When would you use a crossover cable?
When connecting “like” devices, such as switch-to-switch, or station-to-station. However, auto-MDX is enabled on most modern Ethernet devices. It examines the signal and automatically decides to use cross-over.
What is the order of colors for TIA/EIA 568A?
white / green green white / orange blue white / blue orange white / brown brown
What is the order of colors for TIA/EIA 568B?
white / orange orange white / green blue white / blue green white / brown brown
What is a 66 block?
• Type of patch panel • The left side is patched straight across to the right side • Often used in analog and voice connections, and old digital standards. • wires are punched into block
What is a 110 block?
• Designed to replace the 66 block • supports higher speed networks, Cat 5 and 6 cables • wires are punched into block, then connecting block is added on top of it, and additional wires are punched into connecting block • may have RJ45 connectors on the other side