c172 - Module 1 - TCP/IP and Open Systems Interconnection (OSI) Models

In the TCP Model, what does the Application Layer do?

-responsible for the communication protocols between nodes. -deals with information added to an application, such as HTTP, Simple Mail Transfer Protocol, and Domain Name System (DNS)

What are the two primary models used in networking?

-The Transmission Control Protocol and Internet Protocol (TCP/IP) model. -Open Systems Interconnection (OSI).

In OSI Model, describe the physical layer.

-The physical layer contains cabling and connectors. -It establishes how a signal crosses a wire and/or the airwaves.

In TCP/IP model, what does the Transport Layer do?

-This layer is responsible for the end-to-end transport of data. -The protocols that live in this layer are transmission control protocol (TCP) and user datagram protocol (UDP).

In OSI Model, what does the presentation layer do?

-deals with data encryption

What does the transport layer do?

-ensures data is delivered to the correct application -The data transfer is done through Transmission Control Protocol (TCP) or the User Datagram Protocol (UDP).

In OSI model, what does the session layer do?

-establishes the session and ensures things are working correctly end-to-end. -Request and Receive responses

Why is TCP considered reliable?

-in terms of delivery, it verifies the data and resends it if not delivered

In TCP/IP Model, what is the Network Interface Layer comprised of?

-it contains the physical cabling or the wireless spectrum in case of a wireless network

In OSI model, what does the Transport Layer do?

-provides services to the application layer and receives services from the network layer. -responsible for the reliable delivery of data. -segments and reassembles data in the correct order for it to be sent to the receiving device. -handle the reliable delivery of data and any retries of data that are lost. -called the 'Heart of OSI'

Give an example of when UDP would be better to use than TCP.

In audio, where any retransmitting of any lost audio after a few seconds would ruin the experience.

In OSI model, what is layer 1?

Physical

Which layer of the OSI model represents electrical signals, cables, and network cards?

Physical (layer 1)

In OSI model, what is layer 6?

Presentation

Which transmission control protocol/internet protocol (TCP/IP) layer translates messages from one code to another if needed?

Presentation layer

TCP

Transmission Control Protocol

In OSI model, what is layer 4?

Transport

Which layer of the OSI model handles what TCP/IP options are used, including port numbers?

Transport (Layer 4)

In OSI model, which layer is called the 'Heart of OSI'?

Transport Layer

Which transmission control protocol/internet protocol (TCP/IP) layer handles the protocol in connectivity between hosts?

Transport layer

UDP

User Datagram Protocol

In OSI model, what does the Network Layer do?

-Responsible for the transmission of data between hosts in different networks as well as routing of data packets. -implemented through the use of devices such as routers and some switches.

In OSI Model, what does the application layer do?

-Takes care of HTTP, DNS, and FTP

Int OSI Model, what segments does the bottom layer consist of?

-The Physical -The Data Link

What 3 components make up the OSI Application Layer?

-Application -Presentation -Session

What are the 7 layers of the OSI Model?

-Application -Presentation -Session -Transport -Network -Data Link -Physical

What are the 4 layers of the TCP Model?

-Application -Transport -Network -Network Interface

What are the 4 layers that make up the TCP/IP Model?

-Application -Transport -Network -Network Interface

In TCP/IP model, what does the Network Layer do?

-Defines the logical transmission protocols for the whole network. -The main protocols are Internet Protocol (IP), Internet Control Message (ICMP), and Address Resolution Protocol (ARP).

In OSI Model, describe the data link layer.

-Includes network card -Has Media Access Control (MAC) Address

Which two segments can be found on both TCP/IP Model and OSI Model?

-Network -Transport

In both TCP/IP and OSI models, they contain this segment where Internet Protocols (IP) and Internet Control Message Protocols (ICMP) run.

-Network segment

In OSI model, what does the Data Link Layer do?

-responsible for the error-free delivery of data to the receiving device or node. -implemented through the use of devices such as switches and bridge devices as well as anything with a network interface like wireless or wired network cards.

In OSI model, what does the Physical Layer do?

-responsible for the physical connections of the devices in the network. -Implemented through the use of devices such as hubs, repeaters, modem devices, and physical cabling.

How many layers does the TCP/IP model have?

4

How many layers does the OSI model have?

7

In OSI model, what is layer 7?

Application

Which layer of the OSI model provides services such as email and file transfer?

Application (layer 7)

Which transmission control protocol/internet protocol (TCP/IP) layer handles what sockets will be used to connect?

Application layer

In OSI model, what is layer 2?

Data Link

Which layer of the OSI model does a bridge use to make decisions about forwarding data packets?

Data Link (Layer 2)

In TCP/IP model, what does the Network Interface Layer do?

Establishes how data should be physically sent through the network.

In OSI model, what is layer 3?

Network

Which layer of the OSI model moves packets from one IP network to another and provides routing decisions?

Network (layer 3)

Which transmission control protocol/internet protocol (TCP/IP) layer performs addressing and routing?

Network layer

In OSI model, what is layer 5?

Session

Which layer of the OSI model establishes, manages, and terminates connections?

Session (layer 5)

Why is UDP considered unreliable?

it doesn't guarantee redelivery of the data

In OSI model, what does the Session Layer do?

responsible for connection establishment, session maintenance, and authentication

In OSI model, what does the Application Layer do?

responsible for network applications (like HTTP or FTP) and their production of data to be transferred over the network.

In OSI Model, what does the Presentation Layer do?

responsible for translating data from the application layer into the format required to transmit the data over the network as well as encrypting the data for security if encryption is used.