TCP stands for Transmission Control Protocol a communications standard that enables application programs and computing devices to exchange messages over a network.
It is designed to send packets across the internet and ensure the successful delivery of data and messages over networks.
The TCP/IP Model contains 4 layers
- Process/Application Layer
- Host-to-Host/Transport Layer
- Internet Layer
- Network Access/Link Layer
Process Layer
- This layer performs the functions of the top three layers of the OSI model: Application, Presentation, and Session Layer.
- It is responsible for node-to-node communication and controls user-interface specifications.
Some protocols used in the Process Layer are:
- HTTP and HTTPS - HTTP stands for Hypertext transfer protocol. It is used by the World Wide Web to manage communications between web browsers and servers.
- SSH - SSH stands for Secure Shell. The reason SSH is more preferred is because of its ability to maintain an encrypted connection. It sets up a secure session over a TCP/IP connection.
Transport Layer
- This layer is responsible for end-to-end communication and error-free delivery of data.
- It shields the upper-layer applications from the complexities of data.
The two main protocols present in this layer are :
Transmission Control Protocol (TCP) - It is known to provide reliable and error-free communication between end systems. It performs sequencing and segmentation of data.
User Datagram Protocol (UDP) - On the other hand does not provide any such features. It is the go-to protocol if your application does not require reliable transport as it is very cost-effective. Unlike TCP, which is a connection-oriented protocol, UDP is connectionless.
Internet Layer
This layer parallels the functions of OSI's Network layer.
It defines the protocols which are responsible for the logical transmission of data over the entire network.
The main protocols residing at this layer are :
IP - stands for Internet Protocol and it is responsible for delivering packets from the source host to the destination host by looking at the IP addresses in the packet headers. IP has 2 versions: IPv4 and IPv6. (know more about IPv4 and IPv6 )
- ICMP - stands for Internet Control Message Protocol. It is encapsulated within IP datagrams and is responsible for providing hosts with information about network problems.
Link Layer
This layer corresponds to the combination of the Data Link Layer and Physical Layer of the OSI model.
It looks out for hardware addressing and the protocols present in this layer allow for the physical transmission of data.