TCP IP Model Explained | TCP IP Model Animation | TCP IP Protocol Suite | TCP IP Layers | TechTerms

Summary

This script explores the fundamentals of communication in computer networks, emphasizing the importance of shared protocols like TCP/IP for successful data exchange. It explains the layered structure of network communication, detailing each layer's role from the physical to the application layer. The script clarifies the distinction between TCP and UDP, highlighting TCP's reliability and UDP's efficiency. It also delves into concepts like MAC and IP addressing, routing, and the significance of the OSI model in networking research.

Takeaways

• 🌐 For successful communication, both parties must share a common language or message format, which in computer networks, is referred to as a protocol.
• 💬 In computer networks, the message format includes information such as message length, data content, and sender/receiver addresses to ensure successful communication.
• 🔠 If computers use different character encodings like ASCII and Unicode, translations are necessary for successful communication unless a common standard is agreed upon.
• 📚 TCP/IP is a set of protocols that facilitate network communication, including the transmission of various digital forms such as files, voice, and video.
• 🔄 TCP breaks messages into segments and IP handles routing these segments to their destination, with the receiver's TCP module reassembling them into the original message.
• 🔄 TCP stands for Transmission Control Protocol, ensuring reliable communication, while UDP (User Datagram Protocol) is less reliable but faster.
• 🌐 The OSI model and TCP/IP model are network models; the former is for research, and the latter is practical and used in the Internet.
• 🔀 The TCP/IP protocol suite includes multiple layers, each with specific functions, from the physical layer that deals with actual signal transmission to the application layer that generates messages.
• 🔌 The physical layer is responsible for converting binary data into signals suitable for the transmission medium, such as electrical, light, or radio signals.
• 🔗 The data link layer, including MAC and LLC sublayers, manages data encapsulation, media access, flow control, and error detection using Ethernet frames.
• 🛣️ The network layer, also known as the internetworking layer, is in charge of logical addressing, routing, and path determination using IP addresses.
• 🔒 The transport layer uses TCP for reliable, ordered data transfer with features like error checking, retransmission of lost data, and congestion control, while UDP is used for less reliable but faster communication without these features.
• 🌟 The application layer interacts with user applications, providing protocols for accessing network information and services such as HTTP, FTP, and SMTP.

Q & A

What is the fundamental requirement for successful communication between two people?

For successful communication between two people, they must share a common language and be able to understand each other.

Why is a common message format necessary in computer networks?

A common message format is necessary in computer networks to ensure that computers can understand the length of the message, the data part, and the sender's and receiver's addresses, leading to successful communication.

What is the role of protocols in computer networks?

Protocols in computer networks are the agreed-upon set of ground rules that facilitate communication by establishing standards for data exchange and addressing.

How does the TCP/IP protocol suite support network communication?

The TCP/IP protocol suite supports network communication by providing a set of protocols that handle various aspects of data transmission, including message segmentation, routing, and ensuring reliable data delivery.

What is the main difference between TCP and UDP protocols?

TCP is highly reliable but slower, ensuring in-order delivery and error checking, while UDP is less reliable but generally faster, lacking some of the reliability features of TCP.

What is the purpose of the OSI model in network communication?

The OSI model, or Open System Interconnection reference model, is primarily used for research and provides a framework for understanding and designing communication systems, different from the practical TCP/IP model.

What is the significance of the Application layer in the TCP/IP model?

The Application layer is the topmost layer in the TCP/IP model, responsible for generating messages and interacting with user applications to perform network-related activities.

How does the Physical layer in the TCP/IP model contribute to communication?

The Physical layer is responsible for converting binary sequences into signals suitable for transmission over various types of media, such as copper cables, optical fibers, or air for wireless communication.

What is the function of the Data Link layer in the TCP/IP model?

The Data Link layer is responsible for data encapsulation, accessing the media, error detection, and flow control, ensuring reliable transmission of data within a network.

What are the key functions of the Network layer in the TCP/IP model?

The Network layer is responsible for logical addressing, routing, and path determination, ensuring that IP packets are directed to their correct destination across different networks.

How does the Transport layer ensure reliable data transfer using TCP?

The Transport layer ensures reliable data transfer using TCP through features like connection establishment, error-free data transfer via checksums, ordered-data transfer with sequence numbers, retransmission of lost data, discarding duplicate packets, and congestion throttling.

What are some common protocols used by the Application layer for accessing network information?

Some common protocols used by the Application layer include DNS for translating IP addresses and domain names, DHCP for assigning IP addresses, FTP for file transfers, HTTP for web page transfers, and SMTP for email messaging.

Outlines

00:00

🗣️ Communication and Protocols in Computer Networks

This paragraph discusses the fundamental concept of communication, emphasizing the need for a common language or protocol in both human interaction and computer networking. It explains that for successful communication, computers must share a common message format and understand various aspects of the message, such as length, data, and addresses. The paragraph introduces the TCP/IP protocol suite as a set of rules that facilitate network communication, contrasting it with the OSI model, which is more theoretical. It also touches on the basic concept of a network and communication, describing how data is sent in digital form and broken into smaller units for transmission.

05:08

🔌 The Physical Layer and Data Link Layer Basics

The second paragraph delves into the physical layer of networking, which is responsible for the actual transmission of digital messages as signals over various media. It mentions Ethernet as a common protocol and discusses different types of cables used for transmission. The paragraph then transitions to the data link layer, highlighting its two sublayers: MAC and LLC. The MAC sublayer is described as handling data encapsulation and media access, with CSMA/CD as its access method. The LLC sublayer is responsible for flow control and error control, ensuring that data transmission is managed without overwhelming the receiver and that errors are detected and corrected through ARQ.

10:11

🌐 Understanding Routing and the Network Layer

This paragraph explains the network layer's role in logical addressing, routing, and path determination. It describes how IP addresses are assigned to ensure correct delivery and how routing is essential for moving packets between different networks. The paragraph also illustrates the process of routing with an example involving two networks and a router, explaining how ARP is used to resolve MAC addresses within the same network and how routers forward IP packets to their destination. Path determination is discussed as the process of choosing the best route for data delivery, with protocols like OSPF, BGP, and IS-IS being mentioned.

15:16

🚀 Transport Layer Functions and TCP/UDP Protocols

The fourth paragraph focuses on the transport layer, detailing the functions of TCP and UDP protocols. It explains that TCP provides reliable, ordered data transfer with features like error checking, retransmission of lost data, and congestion control, while UDP is faster and less reliable, lacking these features. The paragraph outlines the three phases of data transmission via TCP: connection establishment, data transfer, and connection termination. It also describes the process of the TCP three-way handshake for establishing a connection and the four-way handshake for termination. The paragraph concludes by mentioning the role of the transport layer in segmenting messages and the use of UDP for protocols like DNS, DHCP, SNMP, and RIP.

🌐 Application Layer and Internet Protocols

The final paragraph discusses the application layer of the TCP/IP model, which interacts with user applications to facilitate network communication. It describes the layer as providing access to network information and lists several protocols associated with it, such as DNS, DHCP, FTP, HTTP, IMAP, IRC, POP3, and SMTP. Each protocol is briefly explained in terms of its function, such as DNS for translating IP addresses to domain names, DHCP for assigning IP addresses, and SMTP for email transfer. The paragraph concludes by encouraging viewers to like and share the video for educational purposes.

Keywords

💡Communication

Communication refers to the process of exchanging information between two or more parties. In the context of the video, it is the fundamental concept that underpins both human interaction and computer networking. The script emphasizes the need for a common language or protocol for successful communication, as seen in the example of two people needing to share a common language to understand each other.

💡Protocols

Protocols are the agreed-upon rules that govern the format and transmission of data in computer networks. They ensure that all devices, regardless of their manufacturer, can communicate effectively. The video script explains that protocols like TCP/IP are essential for network communication, providing a set of ground rules for data exchange.

💡TCP/IP

TCP/IP stands for Transmission Control Protocol/Internet Protocol and is a set of protocols used for network communication. The script describes TCP/IP as a practical model developed for the original Internet design, which includes various protocols at different layers to facilitate communication. It is often used synonymously with the Internet itself.

💡Network

A network, in its most basic form, is a group of computers connected together to share data. The video script describes a network as being formed by two computers connected via a LAN cable, using Network Interface Cards to facilitate the exchange of digital messages.

💡Data Units

Data units are the small packets of information that make up a larger message in computer networks. The script explains that messages are broken down into these units for transmission, with different names at different layers, such as segments for TCP, datagrams for UDP, and frames for Ethernet.

💡Ethernet Frame

An Ethernet frame is the unit of data used at the data link layer of a network. The script details that the MAC sublayer of the data link layer is responsible for data encapsulation, which involves adding a header and trailer to form an Ethernet frame, containing the MAC addresses for source and destination.

💡MAC Address

A MAC address, or Media Access Control address, is a unique identifier assigned to a device's network interface card (NIC) by its manufacturer. The video script mentions that the MAC address is used in the data link layer for identifying the sender and receiver in an Ethernet frame.

💡IP Address

An IP address, or Internet Protocol address, is a unique logical address assigned to devices in a network. The script explains that the network layer assigns IP addresses to each segment or datagram to form IP packets, which are essential for routing and ensuring that data reaches the correct destination across different networks.

💡Routing

Routing is the process of moving data packets from one network to another toward their destination. The video script describes how routing is necessary when data is sent to a node outside the local network, and it involves devices like routers that forward IP packets to the next network on the path to the destination.

💡ARP

ARP, or Address Resolution Protocol, is used to map an IP address to a MAC address within the same network. The script explains the role of ARP in providing the MAC address needed to create an Ethernet frame for direct delivery within a network, which is crucial for local communication before data is routed to other networks.

💡UDP

UDP, or User Datagram Protocol, is a transport layer protocol that offers a connectionless service. The script contrasts UDP with TCP, noting that while UDP is faster, it is less reliable and does not guarantee in-order delivery or error checking, making it suitable for applications like DNS and streaming video where speed is prioritized over reliability.

💡TCP

TCP, or Transmission Control Protocol, is a transport layer protocol that provides a reliable, connection-oriented service. The video script describes TCP's features, such as error-free and ordered data transfer, retransmission of lost data, discarding duplicate packets, and congestion throttling, which ensure reliable communication between networked devices.

💡Application Layer

The Application layer is the topmost layer of the TCP/IP protocol suite, which interfaces with user applications. The script explains that this layer uses protocols like HTTP, HTTPS, FTP, and SMTP to perform network-related tasks, providing the means for users to access and exchange information on the network.

Highlights

Communication between two parties requires a common language or protocol.

In computer networks, a common message format is essential for successful data exchange.

Protocols are the agreed-upon rules that facilitate communication in computer networks.

TCP/IP is a set of protocols that support network communication, including the internet.

A network is formed by two computers connected via LAN Cable using Network Interface Cards.

Messages are broken into small data units for transmission and reassembled at the receiver.

TCP segments messages into small units called segments, while IP handles routing to the destination.

TCP is reliable but slower, while UDP is faster but less reliable.

TCP/IP is a practical model developed for the original Internet design, unlike the OSI model used for research.

The TCP/IP model consists of multiple protocols layered at different levels.

The Application layer generates messages that are passed down to lower layers for encapsulation.

The Physical layer is responsible for converting binary data into signals for transmission.

The Data Link layer manages data encapsulation and media access with protocols like Ethernet.

The Network layer handles logical addressing, routing, and path determination with protocols like IP.

Transport layer protocols like TCP and UDP provide services such as flow control, error control, and packet sizing.

TCP ensures reliable data transfer through a three-way handshake, error checking, and congestion control.

The Application layer uses protocols like HTTP, FTP, and SMTP for various internet services.

Transcripts

Suppose two persons are to  communicate with one another.  

To communicate successfully, they  should be sharing a common language.  

Therefore, both ends should be able to  understand what the other person is saying.  

Similarly, in computer networks, the computers  should be sharing a common message format.  

They should know how long the message  is? Which part of the message is the  

actual data? Which part of the message  is the sender's and receiver's address?  

Such information will result in successful  communication between computers.  

If one computer speaks ASCII and the other  speaks Unicode, successful communication  

will not occur unless they are prepared to  perform the translations back and forth.  

So, some ground rules are required  to communicate successfully.  

In computer networks, the agreed-upon set  of ground rules that make communication  

possible are called protocols. TCP/IP is a set of protocols that  

support network communication, but what is  a network and what is communication?  

In the most basic form, two computers  connected via LAN Cable sharing data with  

the help of Network Interface Cards (hardware  present in each computer) forms a network,  

and the process of sending messages from  one place to another through a wired or  

wireless medium is called communication. The message can be a file, a voice conversation,  

a streaming video or anything which can  be communicated in digital form.  

These messages are not sent  as a single unit; instead,  

they are broken into small data units. These  data units are transmitted through the network  

and restored at the receiver  into the original message.  

In TCP/IP protocol suite, TCP breaks messages  into small data units called segments and hands  

them off to IP, which deals with routing segments  through the networks to their final destination.  

TCP module in the receiver combines the  segments to form the original message.  

Note that TCP stands for Transmission Control  Protocol and IP stands for Internet Protocol.  

An alternative to TCP is UDP. It stands for User  Datagram Protocol. The main difference is that TCP  

is highly reliable, but it is slow, whereas UDP  is less reliable but generally faster. Both TCP  

and UDP are a part of the protocol suite.  However, due to heavy dependence on TCP,  

and for historical reasons, the entire set  of protocols is referred to as TCP/IP.  

TCP/IP is a network model designed to support  network communication, even if the computers are  

from different manufacturers. There is one  more network model called the OSI model or  

Open System Interconnection reference model. It  is primarily used for research. On the other hand,  

TCP/IP is a practical model developed to meet  the needs of the original Internet design.  

As per the name, TCP/IP seems to be a set  of two protocols only – TCP and IP. However,  

it consists of numerous protocols  bundled at different layers.  

The topmost layer is the Application layer which  generates a message. The message is passed to the  

lower layers at the sending node, where each layer  encapsulates the message from the above layer.  

So, the message sent becomes larger and  larger as it passes down the chain.  

The data unit in the data link  layer is called an Ethernet frame;  

in the network layer, it is called an IP  packet; if it is in the transport layer,  

it is called TCP segment in case of TCP protocol,  and UDP datagram in case of UDP protocol.  

In the application layer, it is  called an application message.  

The peer layer removes the header at the  receiving node and passes the remainder  

upwards layer-by-layer till the message  finally reaches the application layer.  

Let us discuss each layer  one-by-one in more detail.  

We are starting with the bottom-most  layer – the physical layer.  

The physical layer is the place where  actual communication takes place.  

We know that a sequence of 0s and 1s  digitally represents the messages.  

The physical layer converts this binary sequence  into signals and transmits them over local media.  

The signal can be electrical if the  local media is Copper Cable or LAN cable,  

the Light signal in case of Optical Fiber  and a Radio signal in case of Air/Vacuum.  

So, the signal generated by the Physical Layer  

depends on the type of media  used to connect two devices.  

The most common protocol used at  the physical layer is Ethernet.  

The protocol also specifies the type of  cables that can be used for data transmission.  

For example, if the protocol used is Ethernet,  then twisted pair cable, coaxial cable, or fiber  

optic cable can be used for data transmission. If the protocol used is fast Ethernet or gigabit  

ethernet, then twisted pair or fiber optic  cable can be used as local media.  

Next is - THE DATA LINK LAYER The data unit in the data link  

layer is called an Ethernet frame. The data  link layer is divided into two sublayers:  

· Medium-access control or MAC sublayer, and · Logical link control or LLC sub-layer  

The MAC sublayer is responsible for · Data encapsulation, and  

· Accessing the media In data encapsulation,  

the MAC sublayer adds a header and a trailer to  the IP packet received from the network layer.  

The header contains the MAC addresses  of the sender and receiver. The trailer  

contains 4 bytes of error checking data used to  detect errors in the received Ethernet frame.  

What is the MAC address? It is a unique  6-byte address embedded in the NIC of  

a device by its manufacturer. For accessing the media, the access  

method Ethernet uses is called Carrier Sense  Multiple Access/Collision Detection or CSMA/CD.  

In this method, each computer listens to the  cable before sending data through the network.  

If the network is clear, the computer will  transmit. If the first computer is already  

transmitting on the cable, the second computer  will wait and try again when the line is clear.  

Sometimes, two computers attempt to transmit  at the same instant. When this happens,  

a collision occurs. Each computer then stops  transmission and waits a random amount of time  

before attempting to retransmit. Please note, with this access method;  

it is normal to have collisions. However, the  delay caused by collisions and retransmitting  

is very small and does not normally affect  the speed of transmission on the network.  

The next is the LLC sub-layer. It offers · flow control, and  

· error control Flow control is a technique that restricts  

the amount of data that a sender can send without  overwhelming the receiver. The receiving devices  

have a limited processing speed and a limited  memory to store the incoming data. If these limits  

are exceeded, then the incoming data will be lost.  To avoid this, the receiver should inform the  

sender to slow down the transmission rate before  these limits are met. In the data link layer, flow  

control restricts the number of frames the sender  can send without overwhelming the receiver.  

Error control in the data link layer primarily  refers to error detection and retransmission.  

Error detection is done by using the error  checking bytes added in the trailer of the frame.  

The frame retransmission is done  using Automatic Repeat Request  

or ARQ. The receiver sends an ACK to  the sender when a frame is received.  

When the ACK is not received, the sender sends the  frame again. So, if a frame gets lost or damaged,  

then the ACK is not sent. As a result, the  sender sends the frame again. This process  

is called Automatic Repeat Request (ARQ). LLC layer can also re-size the IP packets  

received from the network layer to fit  them in the data link layer frames.  

The transport layer provides most  of the services of the LLC sublayer,  

including flow control, error control, and  sizing of packets; therefore, the services  

of the LLC layer are usually bypassed. The remaining three layers of the TCP/IP  

protocol stack, including network,  transport, and application layers,  

are implemented as software programs  within the computer's operating system.  

Starting with the NETWORK LAYER The transport layer passes TCP segments  

or UDP datagrams to the Network Layer. The  network layer adds logical addresses or IP  

addresses to the TCP segments or UDP datagrams to  form IP packets and then uses routers to send the  

IP packets to other networks. The network layer  also determines the best path for data delivery.  

So the functions of the network layer are: 1. Logical Addressing  

2. Routing 3. Path determination  

IP is the single standard protocol for this  layer. The TCP/IP network layer is also  

called the internetworking layer or IP layer. Logical Addressing: Every computer in a network  

has a unique IP address. The network layer  assigns sender and receiver's IP addresses  

to each segment or datagram to form an IP  Packet. IP addresses are assigned to ensure  

that each IP packet can reach the correct  destination present in different networks.  

Routing Routing is  

a method of moving an IP packet from source to  destination present in different networks. Routing  

is not needed if the source and destination  computers are present in the same network.  

For communications within a  network, the task is usually simple.  

The ARP module takes the destination IP address  from the IP packet and returns the MAC address  

of the destination computer. It is then used  to create an Ethernet frame which is delivered  

directly to the destination as it is present  in the same network, . no routing is needed.  

However, when the message is being sent to a node  outside a network, for example, to the Internet,  

the network layer moves the message from sender  to receiver through routers. Consider two networks  

connected with a router. Computer A needs to  send data to computer B. Please note that both  

computers are present in different networks.  Hence, in this case, routing is needed.  

To create an Ethernet frame, we need the  MAC address of the destination computer.  

However, in this case, the destination is present  in a different network. So, the ARP module cannot  

provide us with the destination's MAC address  because it can provide the MAC address only if  

the computers are present in the same network. So,  the ARP module in network one cannot provide the  

MAC addresses of the computers present in network  two and vice-versa. Since the intermediate to the  

networks is the router R, the destination MAC  address is kept as the router's MAC address, and  

the frame is forwarded to the router. Router finds  that the MAC address in the frame matches its  

address. So, it extracts the IP packet from the  frame and forwards it to the network layer. The  

network layer finds a mismatch for the destination  IP address. So it sends the IP packet down to  

the data link layer and updates the destination  MAC address with the MAC address of computer B.  

But how router knows the MAC address of computer  B? Simple, by using the ARP module. It is one  

network, so the ARP module works here. Finally,  the ethernet frame is delivered to computer B.  

Please note that the destinations IP address  never changes for inter-network communication,  

but the physical address or the MAC  address changes with every hop.  

So, IP addresses are a must to transfer  data among multiple networks.  

Now Path determination: A computer can be connected  

to an internet server or a computer in several  ways. Choosing the best possible path for data  

delivery from source to destination is called  Path Determination. Layer 3 devices use protocols  

such as OSPF (Open Shortest Path First), BGP  (Border Gateway Protocol), IS-IS (Intermediate  

System to Intermediate System) to determine  the best possible path for data delivery.  

Because routing takes place at the network  layer or layer 3, routers and gateways  

are sometimes called layer three switches. IP is unreliable. It does not guarantee delivery  

nor check for errors. These tasks are the  responsibility of the transport layer.  

Let us start discussing the transport layer At the sending node, the transport layer  

receives the message from the application layer.  When the message reaches the transport layer,  

one of the transport layer protocols,  i.e., TCP or UDP, is selected.  

TCP supports segmentation. So, if the message  is large, TCP divides it into smaller pieces  

and adds a header to form a TCP segment. On the other hand, UDP does not support  

segmentation, so the applications  using UDP should send messages  

short enough to fit into one UDP datagram. Note that the data unit in TCP is called  

TCP segment, and the data unit in  UDP is called UDP datagram.  

UDP datagrams are considered unreliable because  there is no guarantee that all datagrams sent  

will be received in the destination and in the  correct order. So, if reliability is needed,  

UDP should not be used. UDP lacks error checking and  

correction. It makes UDP fast and efficient  for DNS, DHCP, SNMP, and RIP protocols.  

UDP is also suited for streaming videos. When the application layer invokes the UDP  

protocol, UDP encapsulates the application  message into UDP datagrams. The datagram is then  

passed to the network layer for transmission. At the receiving end, the network layer sends  

the UDP datagram to the transport layer. UDP then  extracts the application message from the datagram  

and passes it to the application layer. TCP, on the other hand, is reliable and  

guarantees in-order delivery of data from the  sender to the receiver. The data transmission  

via TCP has three phases: · Connection establishment  

· Data transfer, and · Connection termination  

In the Connection Establishment phase, the sender  TCP or client sends a packet to the receiver TCP  

or server requesting a connection. The server then  sends an acknowledgement to the client. The client  

further acknowledges the server. It completes  the process of connection establishment. Since a  

connection is set up before data transmission,  TCP is a connection-oriented protocol,  

and the connection establishment process is  called Three-Way TCP Connection Handshake.  

Once the connection is established,  the next phase is the Data Transfer.  

During data transfer, TCP offers some key features  which UDP does not provide, and it includes  

• Error-free data transfer • Ordered-data transfer  

• Retransmission of lost data • Discarding duplicate packets, and  

• Congestion throttling Let us discuss each feature one-by-one.  

Error-Free Data Transfer is provided by using  the field Checksum. The sender calculates and  

enters a value in this field. At the receiving  end, the receiver performs the same process  

and calculates the checksum value. If it does  not match with the value present in the checksum  

field, the TCP segment is discarded, and no  ACK is sent to the sender. Because the sending  

side does not receive an acknowledgement of  the discarded packet, it is retransmitted.  

Ordered-Data Transfer TCP adds a sequence number in the TCP segments.  

At the receiving end, the TCP module uses the  sequence numbers to reconstruct the application  

message in the correct order. Retransmission of Lost segments  

For reliable data transfer, the receiver TCP sends  an acknowledgement to the sender TCP for each TCP  

segment it receives. If an acknowledgement is  not received, the TCP segment is retransmitted.  

Therefore, if a TCP segment is lost, the receiver  will not send an ACK message to the sender.  

As a result, the sender TCP  sends the lost segment again.  

Discarding Duplicate segments The TCP client retransmits packets that  

it determines to be lost. However, the receiver  TCP may receive segments that were considered to  

be lost after the sending side has retransmitted  the segments. As a result, the receiving end will  

have two or more copies of the same segment. In  such cases, the unique sequence numbers in the TCP  

header of every segment helps to determine the  duplicate segments, which are then discarded.  

Congestion Throttling or flow control The goal for TCP is to send segments to  

the receiving end as fast as possible without  losing them. When TCP first sends the segments,  

it sets a timer. If the segments are acknowledged  before the timer expires, TCP increases the  

transmission speed until the segments begin to  become unacknowledged. Since the ACK for some  

segments is not received within the time, the  sending TCP module retransmits the segments.  

When a significant number of packets have  to be retransmitted, TCP slows down the  

data transfer rate. In this way, TCP handles  congestion throttling or flow control.  

The last phase in the data transmission  is Connection Termination.  

When an endpoint wishes to stop its connection,  it sends a finished message to the other endpoint.  

The other end acknowledges the message. Both  ends do this two-phase handshake process.  

Therefore, the connection termination follows  a four-way handshake process.  

The Top Most Layer in the  TCP/IP protocol suite is the  

Application layer  

The application layer is used by user applications  that pass messages from one computer to another in  

layer protocols to perform their activities. For example, web browsers use HTTP  

or HTTPS – to do web surfing. Email  programs, such as Microsoft Outlook, use  

post office protocol (POP) or the Simple Mail  Transfer Protocol (SMTP) for transferring emails.  

So, the application layer provides means  to access information on the network.  

This is a list of protocols  provided by the application layer  

DNS - Domain Name System translates IP  addresses into Domain Names and vice-versa.  

DHCP - Dynamic Host Configuration Protocol  automatically assign IP addresses to  

computers present in the network. FTP - File Transfer Protocol is used  

to transfer files on the Internet HTTP - HyperText Transfer Protocol  

is used for sending and receiving webpages IMAP - Internet Message Access Protocol is used  

for email messages on the Internet IRC - Internet Relay Chat protocol  

is used for Internet chat. POP3 - Post Office Protocol  

Version 3 is used by email clients to  retrieve messages from remote servers  

SMTP - Simple Mail Transfer Protocol is  used for email messages on the Internet  

It completes the TCP/IP protocol suite. If you have learnt something from this video, then  

please like this video. Share this video so that  more people can learn. Thanks for watching.