Ch 2 Network Models

Question 1

Modeling

Answer 1

Critical to networking, used to understand networks and to communicate with other techs about networks

Question 2

What is the OSI seven Layer Model

Answer 2

The OSI seven layer model defines the role played be each protocol and it provides common jargon for network techs to use to describe the function of any network protocol.

Question 3

TCP/IP is?

Answer 3

A four layer model that applies only to networks that use TCP/IP protocol switch such as the internet.

Question 4

OSI Layer 1

Answer 4

The physical layer, includes anything that moves data from one system to another, such as cabling or radio waves.

Question 5

OSI Layer 2

Answer 5

The data link layer, defines the rules for accessing and using the physical layer. Divided into two layers Media Access Control (MAC) and the Logic Link Control (LLC)

Question 6

What is the LLC, logic link control?

Answer 6

The LLC sublayer handles the multiple network protocols and provides flow control.

Question 7

What is the MAC sublayer?

Answer 7

The MAC sublayer creates and addresses the frame. It adds the NIC’s own MAC address and attaches MAC addresses to the frames and adds or checks the FCS

Question 8

What is FCS

Answer 8

FCS is a frame check sequencer, and it uses a type of math called cyclic redundancy check (CRC) that the relieving NIC uses to verify the data arrives intact.

Question 9

OSI Layer 3

Answer 9

The network layer, it’s the last layer to work directly with hardware. It creates and addresses packets. The IP addressing enables routers to make sure the packets get to the correct system without worrying about the type of hardware used for the transmission.

Question 10

Logical addressing

Answer 10

Anything that works with logical addressing works at the network layer or layer 3

Question 11

Network protocol

Answer 11

Creates unique identifiers for each system and also creates a set of communication rules for issues such as hot to handle data chopped up into multiple packets and how to make sure they get from one subnet to the next

Question 12

OSI Layer 4

Answer 12

The transport layer, breaks up data received from upper layers into smaller pieces for transport and then adds sequencing numbers for TCP segments to make sure the receiving computer can reassemble the data properly.

Question 13

OST Layer 5

Answer 13

Handles the process of differentiating between various types of connections on a pc. Initiates, accepts and open/closes existing sessions. You can use netstat to view existing sessions

Question 14

OSI Layer 6

Answer 14

The presentation Layer.

Question 15

What does the OSI Layer/presentation layer do?

Answer 15

Translates data from the lower layers into formats usable by the application layer. It also translates from the application layer to lower layers.

** important function: encryption that makes e-commerce possible

Question 16

OSI Layer 7

Answer 16

The application layer. Defines a set of tools that programs can use to access the network.

**application Layer programs provide services to the program that the users see

Question 17

Describe the major functions of the TCP/IP Model

Answer 17

The link layer, the internet layer, the transport layer, and the application layer

Question 18

OSI Seven layers

Answer 18

The physical layer, the datalink layer, the network layer, the transport layer, the session layer, the presentation layer and the application layer.

Question 19

TCP/IP LAYER 1

Answer 19

The internet layer, anything to do with IP, including packets, addressing and network frames.

Question 20

TCP/IP Layer 2

Answer 20

The internet layer, works just like the OSI net work layer. Anything involved with IP (packets, addressing and routing) happens here

Question 21

TCP/IP layer 3

Answer 21

The transport layer. Similar to OSI model’s transport layer, except that TCP/IP version differentiates between connection oriented communication and connection less communication.

Question 22

TCP/IP layer 4

Answer 22

The application layer. Combines the top 3 layers of the OSI model into one super layer.

** session component works similarity to the OSI’s model session layer. There is no presentation component that compares to the OSI model’s presentation layer, however. TCP/IP Layer is like the OSI models version, except that TCP/IP connectivity is implied and not a separate function program