OSI Model

Question 1

OSI

Answer 1

Open Systems Interconnection, 7 layers, 7 to 1 top down, visual model which characterizes and standardizes the communication functions. Each layer serves the layer above it

Question 2

Layer 7

Answer 2

Application Layer. Highest Layer, where the user interfaces with the computer and that’s when our applications / programs run.

File transfers, email, remote terminal access, DNR, etc.

Question 3

Layer 6

Answer 3

Presentation Layer, provides translation to/from the application layer. How images or data are presented. Performs data encryption, decryption, compression, decompression.

Question 4

Layer 6 Protocols

Answer 4

Associated with file formats/protocols such as .jpg, .mpeg, .png, TLS, SSL, Voice Codecs

Question 5

Layer 7 Protocols

Answer 5

FTP (File transfer protocol) and Telnet (depreciated), HTTP, SSH

Question 6

Layer 5

Answer 6

Session Layer. Coordinates, establishes, manages, and tears down sessions between applications on either side of the connection.

Responsiblefor coordinating these connections and tears down these connections

Question 7

Layer 5 Protocols

Answer 7

NetBios, PAP, SIP

Question 8

Layer 4

Answer 8

Transport Layer. Segments and reassembles data from upper layers and unites them into the same single data stream. Provides flow control for data, loss prevention, as well as reliable and unreliable transport methods

Question 9

Layer 4 Protocols

Answer 9

TCP (Transmission Control Protocol), UDP (User Datagram Protocol) RTP (Real-time Transport Protocol) ESP (Encapsulating Security Payload)

Question 10

Layer 4 Protocol Data Unit

Answer 10

TCP: Segment if connection transmission

UDP:Datagram if connection-less tramsission

Question 11

Layer 7 Protocol Data unit

Answer 11

Data

Question 12

Layer 6 Protocol Data unit

Answer 12

Data

Question 13

Layer 5 Protocol Data Unit

Answer 13

Data

Question 14

Layer 4 Devices

Answer 14

Firewall

Question 15

Layer 7 Devices

Answer 15

Host Computer/Server

Question 16

Layer 6 Devices

Answer 16

Host Computer/Server

Question 17

Layer 5 Devicecs

Answer 17

Host Computer/Server

Question 18

Layer 3

Answer 18

Network Layer. Routers/Internet Protocols live here. Provides logical network addressing and path determination/routing services. Responsible for packet delivery, fragmentation, and sequencing.

Question 19

Layer 3 Protocols

Answer 19

IP (Internet Protocol), ICMP (Internet Control Message Protocol), EIGRP (Enhanced Interior Gateway Routing Protocol), OSPF (Open Shortest Path First)

Question 20

Layer 3 Devices

Answer 20

Routers, Multi-layer switch

Question 21

Layer 3 Protocol Data Unit

Answer 21

TCP: Packet

UDP: Datagram

Question 22

Networking Layer

Answer 22

The bottom four layers of the OSI model make up the network layers, (from four to one) Transport layer, Network layer, data link layer, physical layer

Question 23

Layer 2

Answer 23

Data Link Layer, subdivided into two sub layers LLC (Logical Link Controller) and MAC (Media Access Control).

Question 24

MAC

Answer 24

Layer 2 sub layer, Media access control, delivers frames using unique hardware addressing

Question 25

LLC

Answer 25

Layer 2 sub layer, Logical Link Controller, provides error detection and control

Question 26

Layer 2 Protocol Data Unit

Answer 26

Frame

Question 27

Layer 2 Protocols

Answer 27

LLC, MAC, 802.3 (Ethernet standards) 802.11 (Wifi standards)

Question 28

Layer 2 Devices

Answer 28

Switches

Question 29

Layer 1

Answer 29

Physical Layer. The Wire or Physical Media. Turns raw bits into electrical signaling and defines physical network media.

Question 30

Layer 1 Protocol Data Unit

Answer 30

Bits (0s and 1s)

Question 31

Layer 1 Protocols

Answer 31

Voltage, Pinouts, Cable Specs. Half Duplex, Full Duplex

Question 32

Layer 1 Devices

Answer 32

Hub/Repeater, cables and media

Question 33

Full Duplex

Answer 33

Data can be transmitted in both directions on a signal carrier at the same time. One workstation can be sending data on the line while another workstation is receiving data

Question 34

Half Duplex

Answer 34

Between two devices, only one device is capable of transmitting and receiving data on a network or bus at one time. Bi-directional but data can only go in one direction at a time

Question 35

All people seem to need data processing

Answer 35

Going down the layers of the OSI Model, A, P, S, T, N, D, P

Question 36

Please do not throw sausage pizza away

Answer 36

Going up the layers of the OSI Model, P, D, N, T, S, P, A