Section 9 - communication and networking

Question 1

Serial Transmission

Answer 1

Data is transferred 1 bit at a time down a single wire.

Question 2

Parallel transmission

Answer 2

Data is transferred several bits at a time using multiple wires.

Question 3

Bandwidth

Answer 3

Measure of the capacity of the channel in which the data is being sent down

Question 4

Bit Rate

Answer 4

Rate at which data is actually being transmitted

Question 5

What does 1 baud represent

Answer 5

1 electronic state change per second

Question 6

Latency

Answer 6

Time delay that occurs when transmitting data between devices

Question 7

What are the 3 causes of latency

Answer 7

Propagation latency
Transmission latency
Processing latency

Question 8

Propagation latency

Answer 8

The amount of time it takes for a logic gate within a circuit to transmit the data

Question 9

Transmission latency

Answer 9

The amount of time it takes to pass through a particular communication

Question 10

Processing latency

Answer 10

The amount of time it takes data to pass around a network depending on how many devices or servers it has to pass through

Question 11

Asynchronous data transmission

Answer 11

Data is transmitted between two devices that do not share a common clock signal.

Question 12

Synchronous data transmission

Answer 12

The pulse of the clock of both devices are in time and the data is transmitted in accordance with this pulse.

Question 13

FTP

Answer 13

File Transfer Protocol

Question 14

What is the defintion of TCP/IP and what does it do

Answer 14

(Transmission Control Protocol/ Internet Protocol)
Handles the routing and re-assembly of data packets.

Question 15

NIC + what it does

Answer 15

(Network Interface Card)
Allows devices to connect to a network

Question 16

Network

Answer 16

Devices that are connected together to share data and resources

Question 17

Star Topology

Answer 17

It connects devices in a network where each workstation has a dedicated cable to a central computer or switch.

Question 18

Advantages of star topology

Answer 18

-Fast connection speed
-Will not slow down as much when many users are online
-Fault finding is easier
-Relatively secure
-New clients can be added without affecting the other clients
-If one cable or client fails, only that client is connected.

Question 19

Disadvantages of star topology

Answer 19

-Expensive to set up
-If the cable fails then that client may not be able to receive data.
-Difficult to install
-Server can become congested

Question 20

Bus topology

Answer 20

A network layout that uses one main data cable as a backbone to transmit data.

Question 21

Advantages of bus topology

Answer 21

-Cheap to install
-Easy to install
-Easy to add new clients

Question 22

Disadvantages of bus topology

Answer 22

-Less secure
-Transmission times get slower as more users are on the network
-If the main cable fails, all clients are affected
-Less reliable
-Difficulty in finding faults

Question 23

Peer-to-Peer network

Answer 23

All devices in a network share resources between them.

Question 24

MAC address

Answer 24

(Media Access Card)
A unique code that identifies a particular device on a network.

Question 25

What is the purpose of CSMA/CA and what does it stand for

Answer 25

-Carrier Sense Multiple Access with Collision Avoidance - It allows various devices to transmit data at high speeds without interfering with each other.

Question 26

What does the CSMA/CA protocol do

Answer 26

Before each frame of data is sent, the device using the protocol checks to see if the transmission medium is idle and if its free it will transmit the data but if it is busy it will wait a random amount of time before trying to send it again.

Question 27

What is RTS/CTS and what does it stand for

Answer 27

-Request to Send/ Clear to Send -The RTS node sends a message to the recieving mode and if a CTS message is recieved it transmits the data otherwise if no CTS message is recieved it waits then sends it again.

Question 28

SSID meaning and use

Answer 28

(Service Set Identifier) A 32-character code that acts as an identifier in the header allowing it to be transmitted to the correct WLAN

Question 29

How to keep a wireless network secure

Answer 29

-Change the SSID from the default value and hide it in transmission -Ensure that all devices are WiFi protected access -Use strong encryption -Create a white list of MAC addresses

Question 30

Internet

Answer 30

A global network of networks

Question 31

URL

Answer 31

(Uniform Resource Locator) method of identifying location of resources

Question 32

DNS

Answer 32

(Domain Name Server) A server that contains domain addresses that associate with IP addresses

Question 33

PORT

Answer 33

Used to identify a particular process or application on a network

Question 34

what does POP3 do and what port is it

Answer 34

-Fetches email from the email server -Port 110

Question 35

what does SMTP do and what port is it

Answer 35

-Checks for incoming email on an email server -Port 25

Question 36

NAT

Answer 36

(Network Address Translation) It matches up private IP address with public ones

Question 37

Port forwarding

Answer 37

a method of routing data through additional ports.