TCP IP model
What you will learn here about TCP IP model
- TCP IP model layers
- TCP IP model layers functions
- TCP IP layers protocols
TCP IP model generally is written as a TCP/IP model. TCP IP model stands for the Transmission Control protocol/internet protocol model. TCP IP model has 4 layers where the OSI model has 7 layers. The aim of the TCP IP model and the OSI model is to allow network devices to communicate with one another over the Internet as well as in the Local Area Network. Even though the aim of the TCP IP model and OSI model is the same, the layers of each model do a different functionality.
TCP IP model layers
TCP IP model has 4 layers and those are:
- Link layer
- Internet layer
- Transport layer
TCP IP model and the OSI model layers are shown below.
TCP IP model layers functions
Functions of Link Layer:
The link layer is the first layer of the TCP IP model. The link layer is the combination of the Physical layer and the data link layer of the OSI model.
- The link layer is responsible for sending data bits over the communication medium or media.
- The Link layer decides the communication mode i.e simple or half duplex or full duplex.
- The link layer is responsible for communication among devices of the same network.
- The link layer uses WiFi as well as an Ethernet protocol to allow network devices of the same network to communicate with each other.
Functions of Internet Layer
The Internet layer is the middle layer between the Transport layer and link layer. The Internet layer is similar to network layer of OSI model.
Functions of internet layer is given below:
- Internet Layer converts received segment into packets.
- Internet Layer Adds Source and destination IP address to each packet.
- Internet Layer Responsible for routing of packets.
- Handles network traffic i.e network conjunction.
- Internet Layer adds sequence number to each packet.
- Internet Layer Protocols IP, ICMP, IGMP, IPsec.
Functions of Transport layer
The transport layer is the middle layer between the Application layer and the Internet layer. It receives data or information from the Application Layer. If we send entire data or information together and if we lose that data while sending then we will lose the entire data or information. so it is better to divide that data or information into small parts or units and then send it. So even we lose one to two parts of data while sending and the rest parts will be delivered. This job of dividing data or information into small parts or units is done by Transport Layer. This process of dividing data or information into small parts or units is called Segmentation.
Functions of Transport layer is given below:
- Transport layer does segmentation.
- Transport layer uses TCP and UDP protocols. When transport layer uses the TCP protocol, it gives the guarantee of transmission. When transport layer uses the UDP protocol, it does not give the guarantee of transmission.
- Transport layer is also responsible for retransmission of data if data transmission is failing when transport layer uses TCP protocol.
- Transport layer sends an acknowledgment for successful and unsuccessful message delivery.
- Transport layer protocols TCP, UDP, etc.
If you want to know TCP protocol in detail please visit the below link.
Functions of Application layer
Application layer is the top layer of TCP IP model. The Application layer is responsible for performing functions of top 3 layers of OSI model.
Functions of Application layer:
- The application layer is responsible for receiving webpage request from user or client using the most widely used protocol namely HTTP protocol and displaying response back in the browser.
- Application layer also responsible for sending data or files from one place to another place.
- Application layer is used to send Emails.
- Application is responsible for converting a domain name i.e website name into IP address i.e DNS.
- Application layer also performs functions of the presentation layer of OSI model.
- Application layer also acts as a data translator.
- Application layer is also responsible for data encryption or decryption, compression, and decompression.
- Application layer also performs functions of the Session layer of OSI model.
- The Application layer is responsible for creating a session between client and server.
- The Application layer is also responsible for dialog control means for keeping the track of whose turn it is to transmit.
- The application layer is also responsible for token management i.e preventing two parties from attempting the same critical operation simultaneously.
- Application layer protocols: HTTP, DNS, FTP, SMTP, TELNET, etc
TCP IP layers protocols
The list of TCP IP layers protocols is given below.