Free BICSI Technician Exam Flashcards

The T568A wiring pinout is: white/green, green, white/orange, blue, white/blue, orange, white/brown, brown. It is required in U.S. federal contracts and common in legacy installations; the key rule is to keep the same scheme on both ends of a run.

The T568B wiring pinout is: white/orange, orange, white/green, blue, white/blue, green, white/brown, brown. It is the most common commercial scheme in the U.S. Performance is identical to T568A; the critical rule is to terminate both ends of a run with the same scheme.

Category 6A is rated for 500 MHz and supports 10GBASE-T to the full 100 m channel. Cat 6 is rated to 250 MHz and supports 10GBASE-T only to roughly 37-55 m due to alien crosstalk. Cat 5e is rated to 100 MHz and supports 1GBASE-T.

UTP (Unshielded Twisted Pair) has no shielding. FTP (Foiled Twisted Pair) wraps all pairs in a single foil shield. STP (Shielded Twisted Pair) shields each pair and/or the overall bundle. Shielded cables must be bonded at both ends to drain EMI and prevent antenna effects.

The permanent link is the fixed cabling from the work-area outlet to the TR, max 90 m (295 ft). The channel adds patch and equipment cords to a total of 100 m (328 ft). Certification testers use separate permanent-link and channel adapters.

NEXT is signal coupled from a transmitting pair into a neighboring pair measured at the same (near) end of the cable. Lower NEXT in dB is better. Cat 6A has stricter NEXT limits than Cat 6 because higher frequencies couple more strongly between pairs.

Return loss is signal reflected back to the transmitter from impedance mismatches in the cable or connectors, measured in dB. Higher return loss is better. Large reflections indicate poor terminations, kinked cable, or mismatched category components.

Insertion loss is the reduction in signal strength as it travels through the cable, in dB. It increases with cable length, temperature, and frequency. Cat 6A links must meet tighter insertion loss limits at 500 MHz than Cat 5e/6 at their rated frequencies.

A wire map test verifies pin-to-pin continuity on all eight conductors of an RJ45 run. It detects opens, shorts, crossed pairs, split pairs, and miswires. It is the most basic copper test and must pass before performance tests (NEXT, return loss, insertion loss) are run.

Alien crosstalk is noise coupled from adjacent cables external to the link under test, distinct from internal NEXT. It is the limiting factor for 10GBASE-T over Cat 6 and the reason Cat 6A adds shielding and tighter spacing requirements. ANEXT and AFEXT are measured at the near and far ends respectively.

The RJ45, more precisely 8P8C (8 positions, 8 contacts), is the standard modular plug/jack for terminating twisted-pair cabling at work-area and patch-cord ends. It is crimped to T568A or T568B pinout and mates with keystone jacks and patch-panel ports.

The 110 block is an IDC punchdown block used to terminate twisted-pair copper on patch panels and cross-connects. Wires are seated into slotted contacts with a 110 punch-down tool. It is the most common block in modern LAN cabling and is rated by category (5e/6/6A).

Krone blocks use an LSA-PLUS IDC technique that bends the wire into a V-shaped slotted contact for a gas-tight connection. They are common in European and telecom cross-connects. The Krone punch tool seats and trims the wire in one motion, with a different blade geometry than 110.

BIX is a Canadian-developed (Nortel-origin) IDC punchdown block using a 25-pair layout and a distinct BIX punch-down tool. It is found mostly in legacy Canadian telecom cross-connect fields. Like 110 and Krone, it forms a gas-tight connection without stripping insulation.

The 66 block is an older IDC punchdown block with 50 rows of 4 contacts, historically used for telephone cross-connects. It is not rated for high-frequency LAN performance and is now mostly obsolete for data cabling, replaced by 110-style and modular patch panels.

Singlemode fiber has an 8-9 µm core that supports only one light mode, eliminating modal dispersion. OS1 is indoor tight-buffered (legacy); OS2 is outside-plant loose-tube with lower attenuation (~0.4 dB/km at 1310 nm). Singlemode carries long-haul, high-bandwidth links at 1310 and 1550 nm.

OM1 (62.5/125, ~300 MHz·km) and OM2 (50/125, ~500 MHz·km) are legacy LED fibers. OM3 (2000 MHz·km) and OM4 (4700 MHz·km) are laser-optimized 50/125; OM4 supports 10GbE to 400 m and 40/100GbE short-reach. OM5 is WBMMF adding a 953 nm band for SWDM4.

Multimode typically operates at 850 nm (VCSEL lasers). Singlemode uses 1310 nm (zero-dispersion window, shorter reach) and 1550 nm (lowest attenuation, long-haul and DWDM). The 1625/1650 nm band is reserved for OTDR monitoring on live links without interfering with traffic.

An optical loss budget is the maximum allowable end-to-end attenuation of a fiber link, calculated from cable attenuation plus connector and splice losses at the operating wavelength. It is compared to the receiver sensitivity to confirm adequate system margin. Tier 1 certification verifies the budget with an OLTS.

A fusion splice welds two cleaved fiber ends with an electric arc, producing the lowest-loss (~0.05 dB) and most permanent joint. It requires a precision cleaver and a fusion splicer. The finished splice is protected with a heat-shrink sleeve and stored in a splice tray or closure.

A mechanical splice aligns two cleaved fiber ends inside a precision fixture sealed with index-matching gel. Typical loss is 0.1-0.3 dB, higher than fusion. It is faster and needs no fusion splicer, so it is used for emergency restorations and small jobs, but is less permanent.

A proper cleave must be a clean, flat perpendicular break (typically 0.5° or less off vertical) with no lips or shards. Poor cleave angle is the most common cause of high splice loss. Technicians verify cleave geometry visually before placing fibers in the fusion splicer.

The LC connector uses a 1.25 mm ferrule and a small-form latch resembling a miniature RJ45. It is the most common small-form connector in modern singlemode LAN and data-center links and supports duplex and duplex-latch configurations. LC = 'Little Connector'.

The SC connector uses a 2.5 mm ferrule and a push-pull latching mechanism in a square plastic housing. It is widely used in singlemode telecom and older multimode installations. Its push-pull action suits dense patch panels and is easy to insert and remove.

The ST connector has a 2.5 mm ferrule and a bayonet-style twist-lock coupling. It is an older design common in legacy multimode Ethernet and FTTD installations, now largely replaced by LC and SC. ST = 'Straight Tip'.

MPO (Multi-fiber Push-On) is a multi-fiber connector with 12 or 24 fibers in a single ferrule; MTP is the US Conec premium version compatible with MPO. Both are used in 40/100GbE parallel-optic and high-density data-center links, with polarity methods A/B/C defined by TIA-568.

An OTDR sends a light pulse into a fiber and measures backscattered light and reflections versus distance. It locates connectors, splices, breaks, bends, and macrobends by their signature events and reports their loss and reflectance. OTDR is the Tier 2 certification tool complementing the Tier 1 OLTS.

An OLTS measures end-to-end optical loss at the operating wavelength using a light source at one end and a power meter at the other. Tier 1 certification is the mandatory baseline test for installed fiber links, verifying the loss budget per TIA-568. It does not locate faults like an OTDR.

A copper certifier runs a full suite — wire map, length (TDR), insertion loss, NEXT, PSNEXT, return loss, propagation delay, delay skew — against the category limits (Cat 5e/6/6A) and reports Pass/Fail per TIA-568. It is distinct from a simple continuity tester or qualifier.

A TDR sends a pulse down a copper pair and times the reflection from the far-end open or short to calculate length using NVP (Nominal Velocity of Propagation). NVP is a cable-specific value (~0.6-0.72c) that must be set correctly in the tester or length readings will be wrong.

A gainer appears as an apparent signal increase on an OTDR trace when splicing a smaller-core fiber into a larger-core fiber. The larger core produces more backscatter, so the trace rises after the splice. It is a one-way measurement artifact; testing from both ends and averaging gives the true splice loss.

Propagation delay is the time a signal takes to travel the cable; delay skew is the difference in delay between the fastest and slowest pairs. TIA-568 limits skew to 45 ns per 100 m for Cat 5e/6/6A to protect Gigabit and faster signaling that transmits in parallel across all four pairs.

The NEC, published by NFPA as NFPA 70, is the U.S. electrical code adopted locally. Article 770 covers optical fiber cables, Article 800 communications circuits, and Article 725 Class 1/2/3 signaling circuits. Chapter 3 governs wiring methods and cable markings.

CMP (plenum) is rated for air-handling plenum spaces with the strictest flame/smoke limits. CMR (riser) is rated for vertical shafts between floors. CM (general) is the base rating for non-plenum, non-riser runs. OFNP and OFNR are the corresponding optical-fiber plenum and riser ratings.

TIA-568 defines commercial building cabling: 100 m max channel (90 m permanent link), recognized copper (Cat 5e/6/6A/8), recognized fiber (OM1-OM5, OS2), color codes (T568A/B), and connector pinouts. Widely referenced sub-standards include TIA-568.2-D (copper) and .3-D (fiber).

TIA-607 defines the telecommunications bonding and grounding infrastructure: TMGB, TGB, TBB, and the bonding conductor. It requires all telecommunications grounding to be bonded to the building electrical service ground, ensuring a common reference and a low-impedance fault path.

TIA-569 specifies design and sizing of telecommunications spaces (entrance facility, equipment room, TR, work area) and horizontal/backbone pathways (conduit, tray, raceway). It works with TIA-568 and TIA-607 to form the structured cabling framework.

IEEE 802.3 defines wired Ethernet at the physical and MAC layers, including 10BASE-T, 100BASE-TX, 1000BASE-T, 10GBASE-T, and fiber variants. It specifies signaling rates, distance limits, and supported media; installers reference 802.3 to match cabling categories to the LAN speeds they must carry.

The TMGB is the central reference grounding point for the telecommunications bonding infrastructure, typically in the entrance facility. It is bonded to the electrical service grounding electrode system. All TGBs and the TBB connect back to the TMGB per TIA-607.

A TGB is a grounding busbar in each telecommunications room that bonds racks, equipment, and cable shields to the building grounding system. It is connected to the TMGB by the Telecommunications Bonding Backbone (TBB). TGBs may be daisy-chained only along the TBB.

The TBB is the copper conductor that bonds each TGB back to the TMGB, providing a common reference throughout the building. Per TIA-607 it must be at least #6 AWG and may be supplemented by a TBBIBC (interconnecting bonding conductor) in high-rise buildings to reduce impedance.

Grounding connects equipment to the earth (safety reference). Bonding electrically joins metallic parts so they are at the same potential and provides a low-impedance fault path. In ICT cabling, bonding racks, trays, and cable shields together and to ground prevents potential differences and drain currents.

Firestopping uses approved materials and assemblies to restore the fire-resistance rating of a wall, floor, or ceiling penetrated by cable, conduit, or sleeves. It prevents fire, smoke, and toxic gases from spreading between compartments. Only listed systems tested with the specific penetrating items are code-compliant.

A through-penetration passes completely through a fire-rated assembly (both sides of a wall, or top-to-bottom of a floor). A membrane penetration breaches only one surface, such as a back-to-back outlet box in a wall. Both must be firestopped to maintain the assembly's fire-resistance rating.

F-rating = flame spread resistance time (hours). T-rating = temperature-rise limit on the unexposed side. L-rating = air-leakage limit (smoke containment). W-rating = water resistance (hose-stream test). All are measured in hours; an F-rated 2-hour firestop matches a 2-hour-rated assembly.

A TR houses cross-connects, patch panels, and active equipment serving horizontal cabling to work areas. TIA-569 specifies a minimum 36-in-wide door swinging outward, lighting at least 500 lux at 1 m, one air change per hour, and a dedicated electrical branch circuit with 15-A minimum.

NEC limits conduit fill to 40% for three or more cables, 31% for two cables, and 53% for a single cable by cross-sectional area. For ICT work, installers often apply a 40% fill target plus a 25% future-growth allowance so additional cables can be pulled later without exceeding limits.

PPE for ICT installers includes ANSI Z87 safety glasses for fiber-cleaving and termination, cut-resistant gloves for cable handling, and hard hats/steel-toe boots on construction sites. For arc-flash tasks covered by NFPA 70E, flame-resistant clothing and voltage-rated gloves are required.

Lockout/Tagout is the safety procedure that isolates hazardous energy before service. The authorized worker places a lock and tag on each energy-isolating device and verifies zero voltage with a tested meter. LOTO is required by OSHA (29 CFR 1910.147) before working on energized electrical equipment above 50 V.

As-builts are the record drawings and documents showing the installed cabling plant as actually built: cable routes, lengths, termination labels, test results, and deviations from design. They are delivered at project closeout and are the basis for future maintenance, MACs (moves/adds/changes), and warranty claims.