Chapter 5 Network Cabling

Ethernet Standards for Twisted-Pair Cable

100Base-T Fast Ethernet 100 100 Cat 5 or better 2 pair 1000Base-T Gigabit Ethernet 1000 100 Cat 5 or better (Cat 5e is preferred) 4 pair 10GBase-T 10-Gigabit Ethernet 10,000 100 Cat 6a or Cat 7 (Cat 7 is preferred) 4 pair

Two new standards were recently ratified by IEEE

2.5GBase-T—2500 Mbps, requires Cat 5e or better 5GBase-T—5000 Mbps, requires Cat 6 or better

fiber-optic cable

A cable that transmits data at close to the speed of light along glass or plastic fibers. 2 possible sources: laser—An intense, focused light that can travel extremely long distances with very high data throughput LED (light-emitting diode)—A cool-burning, long-lasting technology used on shorter fiber-optic connections, such as between floors in a building or between a switch and a router

Multiplexing

A form of transmission that allows multiple signals to travel simultaneously over one medium. A multiplexer (mux), is required at the transmitting end of the channel. At the receiving end, a demultiplexer (demux) separates the combined signals.

Crossover Cable

A twisted pair patch cable in which the termination locations of the transmit and receive wires on one end of the cable are reversed.

MMF (multimode fiber)

A type of fiber-optic cable that contains a core with a diameter between 50 and 100 microns, through which many pulses of light generated by a lightemitting diode (LED) travel at different angles. MMF connectors can be classified by the number of fibers

SMF (single mode fiber)

A type of fiber-optic cable with a narrow core that carries light pulses along a single path data from one end of the cable to the other end. Data can be transmitted faster and for longer distances. However, it is expensive. connectors are classified by the size and shape of the ferrule(tip).

Two common sources of noises

Electromagnetic interference(EMI)- Caused by motors, power lines, televisions, copiers, fluorescent lights, microwave ovens, manufacturing machinery, and other sources of electrical activity (including a severe thunderstorm) crosstalk- Occurs when a signal traveling on one wire or cable infringes on the signal traveling over an adjacent wire or cable

Routers two different kinds of ports Ethernet ports & Console port

Ethernet ports allow for network communications and are the type of port used to create LANs through the router. A router's console port is used to communicate with the router itself, such as when making configuration changes to the device.

PDV (packet delay variation)/Jitter

If packets experience varying amounts of delay, they can arrive out of order. Cause streaming video or voice transmissions to pause repeatedly, jump around, or stall out completely. transmission errors are returned to the sender.

speed and duplex mismatch

If you specify a particular speed and duplex that's not supported by the neighboring device

Repeater

It regenerates a digital signal in its original form without the noise it might have previously accumulated.

Transmission Flaws

Noise- can degrade or distort a signal and, on a network, is measured in dB. Attenuation- or the loss of a signal's strength as it travels away from its source. Latency- delay

PoE standard specifies two types of devices:

PSE (power sourcing equipment)—The device that supplies the power PDs (powered devices)—Devices that receive power from the PSE

half-duplex

Signals may travel in both directions over a medium but in only one direction at a time.(walkie)

simplex

Signals may travel in only one direction, and is sometimes called one-way, or unidirectional, communication.(broadcast radio)

Three common types of multiplexing used on copper lines are

TDM (time division multiplexing)—Divides a channel into multiple intervals of time, or time slots. STDM (statistical time division multiplexing)—Assigns time slots to nodes (similar to TDM), but then adjusts these slots according to priority and need. FDM (frequency division multiplexing)—Assigns different frequencies to create multiple frequency bands, each used by a subchannel, so that multiple signals can transmit on the line at the same time.

bandwidth

The amount of data that could theoretically be transmitted during a given period of time.

throughput

The measure of how much data is actually transmitted during a given period of time.

twist ratio

The number of twists per meter or foot. a high twist ratio can result in greater attenuation. For optimal performance, cable manufacturers must strike a balance between minimizing crosstalk and reducing attenuation

straight-through cable.

The wire pairs in the cable connect to the same pin numbers on each end

802.3af standard

a method for supplying electrical power over twisted-pair Ethernet connections, also known as PoE (Power over Ethernet). ex dial tone

Three common types of crosstalk

alien crosstalk—Crosstalk that occurs between two cables NEXT (near end crosstalk)—Crosstalk that occurs between wire pairs near the source of a signal FEXT (far end crosstalk)—Crosstalk measured at the far end of the cable from the signal source

Rollover Cable

also called console cables, are used to connect a computer to the console port of a router

Full-duplex

also called duplex—Signals are free to travel in both directions over a medium simultaneously.

STP (shielded twisted pair)

cable consists of twisted-pair wires that are not only individually insulated, but also surrounded by a shielding made of a metallic substance such as a foil.

twisted-pair cable

consists of color-coded pairs of insulated copper wires, each with a diameter of 0.4 to 0.8 mm

fiber termination kit

fiber stripper—strips off the outer layers of a fiber-optic cable fiber cleaver—cuts a clean slice through the fiber strands

To measure latency on data networks is by calculating a packet's- RTT (round trip time)

or the length of time it takes for a packet to go from sender to receiver, then back from receiver to sender. RTT is usually measured in milliseconds.

TIA/EIA 568

standard divides twisted-pair wiring into several categories

TIA/EIA 568A and TIA/EIA 568B

standard terminations for Fast Ethernet and Gigabit Ethernet

media converter is hardware that enables networks or segments running on different media to interconnect and exchange signals.

stopped at 5-3d

Twisted-Pair Cabling Standards

Cat 3 (Category 3) 10 Mbps Up to 16 MHz Cat 5 (Category 5) 100 Mbps 100 MHz Cat 5e 1000 Mbps(1 Gbps) 350 MHz Cat 6 (Category 6) 10 Gbps 250 MHz

UTP (Unshielded Twisted Pair)

A type of twisted pair cabling that does not include shielding around its conductors.

STP AND UDP highlights and similarities

STP and UTP can both transmit data at 10 Mbps, 100 Mbps, 1 Gbps, and 10 Gbps. STP is more expensive than UTP because it contains more materials and it has a lower demand. It also requires grounding, which can lead to more expensive installation. use both rj 45 modular connector.

Three types of multiplexing technologies are used with fiber-optic cable

WDM (wavelength division multiplexing)- Works with any fiber-optic cable to carry multiple light signals simultaneously by dividing a light beam into different wavelengths, or colors, on a single fiber. DWDM (dense wavelength division multiplexing or dense WDM)- Increases the number of channels provided by normal WDM to between 80 and 320 channels. CWDM (coarse wavelength division multiplexing or coarse WDM)- Lowers cost by spacing frequency bands wider apart to allow for cheaper transceiver equipment.

coaxial cable

insulated copper wire; used to carry high-speed data traffic and television signals.

Fiber's characteristics

throughput—Fiber has proved reliable in transmitting data at rates that can reach 100 gigabits (or 100,000 megabits) per second per channel. cost—Fiber-optic cable is the most expensive transmission medium noise immunity- does not conduct electrical current to transmit signals, it is unaffected by EMI size and scalability Depending on the type of fiber-optic cable used, segment lengths vary from 2 to 40,000 meters. The maximum limit is due primarily to optical loss,