Section 2 : Network Basics

Question 1

What is a client ?

Answer 1

A device used by an end-user to access the network.

Question 2

What is a server ?

Answer 2

A device that provides resources to the rest of the network.

Question 3

What is a hub ?

Answer 3

1. Older technology that connects network devices together.
2. It receives information and rebroadcasts it.

Question 4

What is a WAP ?

Answer 4

A wireless access point is a device that allows wireless devices to connect into a wired netowrk. It’s like a wireless hub.

Question 5

Whats is a switch ?

Answer 5

1. A device that connects network devices together.
2. It is just like a hub. Switches can learn which devices are on which port. A switch can take data and send to one port. This is the big benefit of a switch. That’s why they are also called “smart” hub.

Question 6

What is a router ?

Answer 6

A router connects two different networks together and forward traffic to and from a network. Modern routers use IP.

Question 7

What is a media ?

Answer 7

Connects two devices or a device to a switch port. It can be copper cable, fiber optic cable, or even radio waves.

Question 8

What are WAN links ?

Answer 8

connect two networks that are geographically dispersed. connection to the outside world.

Question 9

the Client/server model ?

Answer 9

Use a dedicated server to provide access to files, scanners, printers and other resources on the network.

Question 10

What are the benefits of a client/server model ?

Answer 10

1. administration, configuration and backup are pretty easy (centralized);
2. better scalability.

Question 11

Drawbacks of client/server ?

Answer 11

1. expansive because specialized OS.
2. more dedicated resources.
   Still the leading model.

Question 12

What is the peer to peer model ?

Answer 12

Peers share resources directly. all the files are located on different machines.

Question 13

drawbacks of P2P ?

Answer 13

1. Work must be done multiple times
2. etg to configure evw. decentralized management is awful when we deal with business network.
3. Backups are difficult contrarily to client/server.
4. horrible scalability.

Question 14

Where is P2P useful ?

Answer 14

for instance Napster.
1. each person give and receive files.
2. low cost (no infrastructure)
3. no specialized OS.
they are opposite on everything.

Question 15

what is a PAN ?

Answer 15

Smallest type of wired or wireless (10 feet or less). Bluetooth and USB. 10 feet or 3 meters. USB connections can be PAN too. hard drive connected on USB it is a serial connection.

Question 16

What is a LAN ?

Answer 16

Connects components within limited distance. Hundred meters. CAT5 cable. Further with fiber. Small office or one floor. Home or class network.

Question 17

What are the standard of the network ?

Answer 17

Ethernet => IEEE 802.3
WIFI => IEEE 802.11

Question 18

Campus Area Network ?

Answer 18

1. Connects LANs that are building centric across a university industrial park.
2. Few miles.
3. each building has its own LAN. within a couple of miles.

Question 19

Metropolitan area network ?

Answer 19

Connects scattered locations across a city or metro are. Up to about 25 miles depending on the size of a city.For instance if a college has different campuses across a city. For instance the connections of different CANs forms a MAN.

Question 20

Wide Area Network ?

Answer 20

1. Connects geographically disparate internal networks and consists of leased lines or VPNs.
2. Cross country or world. Internet is the largest WAN.
3. They don’t always have to be public (company with an office in NY and California). For instance the US gmt has offices everywhere connected with a private WAN.

Question 21

Sum up every networks.

Answer 21

PAN <– LAN <— CAN <— MAN <– WAN

Question 22

What is the difference between a logical and physical topology ?

Answer 22

A logical topology indicates the network flow while a physical topology indicates where are the equipments.

Question 23

Bus topology

Answer 23

1. Single cable where each device taps into by using either a T-connector or vampire tap.
2. old way of connecting network = big cable and each computer has a clamp that bites the big cable. bus topologies are quite old.
3. there is collisions because they talk at the same time.

Question 24

Ring topology ?

Answer 24

Uses a cable running in a circular loop. They have to wait their turn. Travels in a singular direction. We used a token ring passed around from computer to computer to know which computer can talk. it eliminates the collisions.

Question 25

Ring topology vulnerability ?

Answer 25

no redundancy. and collision if no token ring is used.you cut the network and it’s done.

Question 26

What is a FFDI ?

Answer 26

it’s a fiber distribution network. It uses two counter-rotating rings for redundancy. If one’s broken the other takes. Modern ring networks are usually FDDI networks. Now ring = redundancy. For the exam, they talk about FDDI rings.

Question 27

Star topology ?

Answer 27

most popular physical LAN topology. Etg is connected to the switch with fiber, copper or wireless. if the central device fails the entire network fails. Single point of failure. very common and inexpensive but this vulnerability.

Question 28

Hub and spoke topology ?

Answer 28

used to connect multiple site together. Similar to star but with WAN links instead of LAN connections and it used for connecting multiple sites. you go first to the hub and then you move elsewhere. you can’t avoid the hub nodes. If a hub node fails it is still beter than a single star.

Question 29

Full mesh topology?

Answer 29

Optimal routing is always available as every node connects to every other node. very expansive and hard to put in place. A lot of connections and a lot of machines. we never gonna see a full mesh in a physical network.

Question 30

Does network topologies apply to wireless network topologies ?

Answer 30

Yes but some topologies are specific : infrastructure mode ;
ad hoc ;
Wireless mesh topology.

Question 31

What is infrastructure mode ?

Answer 31

Common type of wireless network. Uses a wireless access point as a centralized point and supports wireless security controls.

Question 32

What is ad Hoc mode ?

Answer 32

Decentralized wireless network which creates P2P connections and does not require a router or access point.

Question 33

What is a wireless mesh ?

Answer 33

Interconnection of different types of nodes, devices or radios. we can use different frequencies into a single wireless network. It creates redundant and reliable connections. we can use after there’s a hurricane.

Question 34

What is 802.11 ?

Answer 34

Wireless networks that can operate in infrastructure or ad hoc modes.

Question 35

What is bluetooth ?

Answer 35

Low-energy use variant of bluetooth which allows for a mesh network. Your keys can talk to your cellphone. (IoT related)

Question 36

What is RFID ?

Answer 36

(IoT related) Uses electromagnetic field to read data stored embedded. Such as key hotel. Awarehouse could utilize RFID to allow for the accurate scanning of items using radio frequency tracking tags and sending data of up to 2 KB to a sensor at rapid speeds.

Question 37

What is NFC ?

Answer 37

Enables two devices to communicate within a 4 cm range. For instance Apple Pay. (IoT related)

Question 38

What is Infrared ?

Answer 38

technology used by IoT that we can see in the TV command. Much older technology and not used heavily.

Question 39

What is Z-Wave ?

Answer 39

1. It is a technology used by IoT that provides short-range,
2. low latency data transfer with
3. slower rates and less power consumption than WI-FI.
4. Home automation mostly.

Question 40

What is ANT+ ?

Answer 40

technology used by IoT that collects and transfers of sensory data. for instance a tire pressure system. Tire pressures, TVs, lights and so on. Anything with a sensor on it.