Net+, Chapter 3, Networking Connectors and Wiring Standards

coaxial

cable type, contains a center conductor made of copper that's surrounded by a plastic jacket with a braided shield over it

plenum-rated coating

a coating that allows a cable to be installed in plenum, essentially fire retardant, expensive

BNC

connector for thinnets

plenum

space between floors

thinnet

thin ethernet, 10Base2, same as thick coax but only 5mm

relevant coax cables

RG-59 and RG-6

RG-59

Cable television, low cost, short distance

RG-6

Cable television, cable modems, longer distances than RG-59; some power implementations

F-type connector

form of coaxial connector used for cable TV, screws to tighten to the interface, resembles RG-58

twisted pair

cable type, consists of multiple individually insulated wires that are twisted together in pairs

shielded twisted pair

STP, a metallic shield is placed around the pairs

unshielded twisted pair

UTP, does not have outer shielding, supports 10BaseT, 100BaseTX, 1000BaseTX, 10GBaseT, and 40GBaseT

fiber optic

cable type, transmits digital signals using light impulses rather than electricity, carried on glass or plastic core, immune to EMI and RFI

twinaxial

used for short-distance high-speed connections such as 10 and 40G Ethernet in data centers, bulkier, always shielded

direct attach copper

DAC, twinaxial child, has connectors at either end of a fixed-length ~26-28 AWG copper cable for direct device communication

AWG

the smaller the number, the thicker the wire

N<Sig>X

N=signal in megabits per sec, Sig=sig type (base or broad), X=unique identifier for cable scheme

crosstalk

when electromagnetic signals conducted on copper wires in close proximity cause interference

CAT1

Two twisted wire pairs (four wires), limited to 1 MHz frequency, voice grade only, not rated for data communication

CAT2

Four twisted wire pairs (eight wires), handles up to 4 Mbps with 10 MHz frequency limitation, now obsolete

CAT3

Four twisted wire pairs (eight wires) with three twists per foot, up to 16 MHz and 10 Mbps, obsolete for networks

CAT4

Four twisted wire pairs (eight wires), rated for 20 MHz, obsolete

CAT5

Four twisted wire pairs (eight wires), used for 100BaseTX (two pair wiring), rated for 100 MHz

CAT5e

Four twisted wire pairs (eight wires), recommended for 1000BaseT (four pair wiring), rated for 100 MHz, handles disturbance on each pair

CAT6

Four twisted wire pairs (eight wires), used for 1000BaseTX (two pair wiring), rated for 250 MHz

CAT6a

Rated to 500 MHz with improved crosstalk, allows 10GBaseT for up to 100 meters

CAT7

Allows 10 Gigabit Ethernet over 100 meters of copper, contains four twisted copper wire pairs

CAT8

Supports 25G and 40G Ethernet with a 30-meter distance, ideal for data center deployments

registered jack

RJ connector used with UTP; RJ-11 for phones (four wires), RJ-45 for LAN (four pairs, eight wires), RJ-48c used with T1, shielded (obsolete)

RJ-45 usage

mainly LANs up to 100 meters, unshielded

RJ-11 usage

home DSL connections, not LAN

multimode fiber

MMF, high speeds over medium distances (~3,000 feet), cladding focuses light back onto core

single mode fiber

SMF, used for longer distances (40–80 km depending on transceiver)

straight tip

ST, fiber connector, commonly used with SMF, positive locking mechanism

subscriber connector

SC, square fiber connector with a floating ferrule

ferrule

small, rigid tube (ceramic, stainless steel, or plastic) used to align and protect stripped fiber core or conductor

small form factor

connector style allowing more fiber optic terminations

mechanical transfer registered jack (MT-RJ/MTRJ)

one-third size of SC/ST, TX and RX strands in one connector, keyed for single polarity, pre-terminated, easy to use

local connector (LC)

resembles RJ-style connector, popular for Fibre Channel adapters, easier to terminate, cable cannot be disassembled like SC

multi-fiber push on (MPO)

provides 2, 8, 12, or 24 fiber connections in a single connector, fans out to multiple LC connectors, 10–100 Gbps per connection

transmit strand

TX

receiver strand

RX

fibre channel

FC, very high-speed data transfer protocol (2–32 Gbps), delivers raw block data in order and lossless, often connects SANs, switches operate as one large switch

APC

connector end finish, green, angled physical contact, reduces decibel loss

UPC

connector end finish, blue, ultra physical contact, causes return loss

Fiber distribution panels (FDPs)

termination and distribution systems for fiber-optic cable facilities

fiber optic transceivers

can be unidirectional or bidirectional, device with transmitter and receiver

small form factor pluggable

SFP/SFP+, compact pluggable optical module, supports up to 16 Gbps

quad small form factor pluggable

QSFP, interfaces networking hardware to fiber or copper, data rates from 4x1 Gbps to 4x28 Gbps (QSFP28)

media converter

converts one media type to another (SMF to Ethernet, MMF to Ethernet, Fiber to Coaxial, SMF to MMF)

serial cables

RS-232, USB, DB-25

universal serial bus

USB

attenuation

degradation of a signal due to the medium and distance

T568A

wiring standard (green/white, green, orange/white, blue, blue/white, orange, brown/white, brown) symmetrical

T568B

wiring standard (orange/white, orange, green/white, blue, blue/white, green, brown/white, brown) symmetrical

Straight-through

cable connects host/router to switch or hub

Crossover

cable connects switch to switch, hub to hub, host to host, hub to switch, router to host (T568A + T568B)

Rolled/rollover

1↔8, 2↔7, etc., used to connect host EIA-TIA 232 interface to router console serial COM port

wiring standard tip

45 and 78 positions stay the same between standards (B/b and BR/br)

UTP Gigabit Wiring (1000BaseT)

1↔3, 2↔6, 4↔7, 5↔8 both ways

CSU/DSU connection

requires T1 crossover cable

main distribution frame (MDF)

wiring point used as reference for telephone lines, WAN termination point

intermediate distribution frame (IDF)

located in equipment/telecom room, connected to MDF, provides flexibility for distribution, sturdy metal rack holding bulk cables

25-pair cable

consists of 25 wire pairs inside one jacket, mainly for telephone cabling, backbone, and cross-connects, reduces cable clutter

feeder cable

supplies signal to many connected pairs

66 block

standard termination block using 25-pair cable, contains 50 rows, standard for voice cabling

110 block

newer wiring distribution point, wires punched down on one side, RJ-11/RJ-45 connections on the other, supports up to 1 Gbps with Cat6+

bix block

punch-down block, terminates up to 25 cable pairs, slip-in fitting, no pre-stripping required

demarc

last point of responsibility for service provider

smart jack

also called network interface device (NID) or network interface unit (NIU)

CAT 5e UTP cable

fiber to coaxial

MT-RJ connector

multimode fiber to ethernet

registered jack connectors

RJ-45 connector, T568B standard

rolled ethernet cable

SC connector

ST connector

single mode to multimode fiber

T568B

T568A

UTP gb crossover ethernet cable

rolled ethernet cable