physical layer

Question 1

what are nic cards

Answer 1

cards on devices used to connect (wired connection) your device to a network

Question 2

WLAN

Answer 2

wireless local area network
WLAN nics used to connect devices in a wireless connection

Question 3

what is the purpose of the physical layer

Answer 3

accept a data frame from the data link layer and encodes it into bitsand the bits are transformed into a series of signals depending on the media (wireless or wires or fibers )

Question 4

the physical layer standars

Answer 4

the tcp/ip standards are implemented in SOFTWARE and are governed by the IETF

the physical layer standards are implemented in HARDWARE and are geverned by (ISO/IEEE/EIA/TIA)

Question 5

encoding

Answer 5

the process of converting the bits into format recognozable by the next device in the network path

eg of a method manchester

Question 6

signaling

Answer 6

the process is how the bits value 1 and 0 represented on the physcial meduim

Question 7

bandwidth and digital bandwidth

Answer 7

the capacity at which a meduim can carry data

digital bandwidth: how many bits can be transmitted in a sec

Question 8

bandwidth termenology

Answer 8

1. latency: amount of time for data to travel from one point to another including delays
2. throughtput:the measure of the transfer of bits in the media over a given time

3.goodput: the measure of the transferred usable data over the meduim in a given time

goodput=throughtput- traffic overhead

Question 9

charectarstics of copper media

Answer 9

1. the data signlas are transmitted as electrical pulses

2.attenuation: the longer the data signal travel the more it detriorates

3.electromagnetic interfernace or radio freaquency interfernace can affect the data thats being sent in the cable

Question 10

types of copper cables

Answer 10

UTP: unsheilded twisted pair
STP: sheilded twisted pair
coaxial cable

Question 11

utp

Answer 11

most common type
used with rj-45 connector
the twsited pair protect the signal from interfernace crosstalk
it has color coded insulation to identify the pairs

Question 12

stp

Answer 12

better noise protection than utp
more expensive and harder to install
terminated with rj-45 connector
the sheild protects the signal from rfi or emi

Question 13

coaxial cable

Answer 13

consits of (outer cable jacket to avoid physical damage/ metalic foil that protects the inner conductor and the sec wire in the cable/ layer of flixible plastic insulation/copper conductor used to transmit the electronic signals)

Question 14

how does utp limit crosstalk

Answer 14

cancelation: each pair (one is positive the other is negative) cancell each others electrical feilds and the emi/rfi

varation in twists per foot : each pair is twisted a diffrent amount than the other pairs

Question 15

utp standards

Answer 15

standards for the utp are established by the TIA/EIA

electrical standards for the copper cabeling are established by the IEEE

Question 16

straight through cables vr crossover cables

Answer 16

straigh through: connects unlike devices to each other

corssover cable:connect similar devices to eachother (wire 1 swap with 3 wire 2 swap with 6)

Question 17

fiber optic cabeling

Answer 17

transmitts data over longer distance and higher bandwidth

immune to emi/rfi and data is transmitted with less attenuation

bits are encoded in the media are light pulses