Lesson 1 Explaining the OSI and TCP/IP Models

Question 1

What Are The 7 Layers of OSI Model ?

Answer 1

Layer 1 Physical Layer, 
Layer 2 Data-Link Layer, 
Layer 3 Network Layer, 
Layer 4 Transport Layer, 
Layer 5 Session Layer, 
Layer 6 Presentation Layer, 
Layer 7 Application Layer,

Question 2

OSI Stands For What?

Answer 2

Open System Interconnection

Question 3

TCP/IP Top Layer Is Called Application & Is Combined of What 3 OSI Model Layers?

Answer 3

Layer 5 Session Layer,
Layer 6 Presentation,
& Layer 7 Application Layer

Question 4

TCP/IP Host-To-Host Transport Layer Is the Same as Which OSI Layer?

Answer 4

Layer 4 Transport Layer

Question 5

TCP/IP Internet Layer Is the Same as Which OSI Layer?

Answer 5

Layer 3 Network Layer

Question 6

TCP/IP Network Interface Layer is a combination of Which Two OSI Layers?

Answer 6

Layer 2 Data-Link Layer & Layer 1 Physical Layer

Question 7

What Is a Network Boundary?

Answer 7

Two or more computer systems linked together by some form of transmission medium that enables them to share information

Question 8

What Are Nodes?

Answer 8

Nodes are the devices that communicate on the network

Question 9

What Are Links?

Answer 9

Links are the communications pathways that are found between Nodes

Question 10

PDU Stands for What?

Answer 10

Protocol Data Units

Question 11

What are Two of The Most important functions of Protocols?

Answer 11

Addressing and Encapsulation

Question 12

What Function Direct Data to what path it will take?

Answer 12

Addressing

Question 13

Which Devices Can Be Found at Layer 1 Physical Layer?

Answer 13

Transceiver, Media Converter, Hub/Repeaters & Modem

Question 14

MAC Addresses & Switches are found at which Layer?

Answer 14

Layer 2 Data-Link Layer

Question 15

Which device is used to amplifies an electronic signal so as to extend the maximum allowable distance for a media?

Answer 15

A Repeater

Question 16

Bits Encoding/ Transmission takes place at which Layer?

Answer 16

Layer 1 Physical Layer

Question 17

Switches found at Layer 2 the Data Link Layer forward frames from one port to another port based off what?

Answer 17

The Mac Address plugged into the switch port

Question 18

Routers found in the 3rd layer Network Layer sends what to other routers by moving data between networks?

Answer 18

Packets

Question 19

A NIC, Bridge, Switches & Wireless Access Point (WAP) are devices found at which Layer?

Answer 19

Layer 2 Data-Link Layer

Question 20

IP Address, ICMP, IGMP, ARP, IPsec describe devices found at which layer?

Answer 20

Layer 3 Network Layer

Question 21

A method of grouping data into packets that are transmitted over a digital network

Answer 21

Packet Switching

Question 22

A method of implementing a telecommunications network in which two network nodes establish a dedicated communications channel through the network before the nodes may communicate.

Answer 22

Circuit Switching

Question 23

A form of switching in which data is broken into packets but with the add ability of being stored or forwarded (i.e., like email) goes by what name?

Answer 23

Message switching

Question 24

OSPF is short for?

Answer 24

Open Shortest Path First

Question 25

Router Information Protocol Is also called what?

Answer 25

RIP

Question 26

A request to find the best available route to the destination, when sending a message.

Answer 26

Route Discovery

Question 27

Flow Control prevents what from occurring?

Answer 27

It prevents a sender from sending data faster than the receiver can get it

Question 28

Allowing packets to be sent over more than one link & routes for faster service is named what?

Answer 28

Packet Reordering

Question 29

Layer 4 is named what?

Answer 29

Transport Layer

Question 30

UDP (User Datagram Protocol) is connectionless protocol that defined by RFC 768 that is used for?

Answer 30

Used for performance but can be unreliable

Question 31

The Network Layer identify each application by assigning what to it?

Answer 31

It identifies applications by assigning port numbers to them

Question 32

TCP (Transmission Control Protocol) ensures reliable data delivery through a process that is named?

Answer 32

Three-Way Handshake in which normally a client device would initiate a connection with a server. The client sends a sequence number packet (with the SYN bit set) to the server. The packet contains the random sequence number (e.g., 5432) which marks the beginning of the sequence numbers for data that the server will transmit.

Question 33

The Layer that represents the dialog control functions that administer the process of establishing the dialog, managing data transfer, and then ending (or tearing down) would be which layer?

Answer 33

Layer 5 The Session Layer

Question 34

What is happening at the Session Layer?

Answer 34

The management of a session between two devices and also firewalls protections

Question 35

One-way/simplex—Only one system is allowed to send messages; the other only receives. Two-way alternate (TWA)/half-duplex—The hosts establish some system for taking turns to send messages, such as exchanging a token. Two-way simultaneous (TWS)/duplex—Either host can send messages at any time. Are the 3 modes of which layer?

Answer 35

Layer 5 The Session Layer

Question 36

Compression, Encryption and Formatting all take place during which layer in the OSI process?

Answer 36

Layer 6 The Presentation layer

Question 37

The Presentation Layer does what?

Answer 37

Transforms data between the format required for the network and the format required for the application

Question 38

What is the main purpose of layer 7 (Application Layer) within the OSI Model?

Answer 38

To provide an interface for software programs on network hosts that have established a communications channel through the lower-level protocols to exchange data.

Question 39

Network card driver (Layer 2), Sockets/Winsock (Layer 5) & Web Browsing (Layer 7) are all examples of what?

Answer 39

They are examples of API's (Application Programming Interface) software.

Question 40

A dedicated path established between two locations, such as two routers or two modems.

Answer 40

A Circuit

Question 41

The ability for one host to forward information to another using any available path

Answer 41

Packet Switching

Question 42

A packet switching protocol is described as ?

Answer 42

Robust because it can automatically recover from communications link failures. It re-routes data packets around an internetwork of available paths. If transmission lines are damaged or if a router fails to respond, it can use any available network path that remains.

Question 43

The process for adopting Internet standards revolves around the production of documents called ?

Answer 43

Requests for Comments (RFCs)