What is TCP/IP?

Overview of TCP/IP

TCP/IP, Short for Transmission Control Protocol/ Internet Protocol, is a communication protocols suite that means a set of rules and procedures which are used for interconnecting various network devices over the internet by defining how the data should be transmitted, routed, broken into packets, addressed, and received at the destination. The TCP defines how applications can create communication channels across a network. IP defines the way each packet is addressed and routed to ensure it reaches the correct destination.

How does TCP/IP works?

The functionality of TCP/IP is divided into five layers -1)Physical Layer, Data Link Layer, Network Layer, Transport Layer, Application Layer.

Physical Layer

• Physical Layer converts binary data into signals and transmits over the local media. In this layer, a unit of communications is a single bit. When the connection is established between two devices, data flows in the form of a stream of bytes. The physical layer delivers bits.

Data Link Layer

• Data Link Layer defines the format of the data on the network. Physical addressing is done in the Data Link Layer. MAC Address of source and destination are assigned to the data packet to form a frame.
• In the data link layer, the unit of communication is a frame. This layer divides the message or file into the frame. The frame is nothing but a packet that is responsible for encapsulating the data received from the network layer.

Network layer

• In the network layer, the unit of communication is a Packet. This layer provides an IP Address of the source and destination to each segment to form a packet. Network Layer provides functions such as Logical addressing, i.e. IP Addressing, Path determination and routing. Routing is a method of moving data packets from source to destination.
• Based on the IP Address and mask, routing decisions are made in the network. At the same time, Path Determination is the process of choosing the best possible path for data delivery to the receiver. It uses OSPF protocols (Open Shortest Path First), BGP( Border Gateway Protocol), etc.

Transport layer

• The transport layer is responsible for transferring data from one location to another. It controls the reliability of communication through segmentation, flow control, and error control.
• Segmentation is the process of dividing received data into small units called segments.
• A segment is a unit of Communication In this layer.
• Flow Control: Flow Control is the process of controlling the amount of data being transmitted.
• Error Control: Transport Layer uses Automatic Repeat Request Scheme to retransmit lost or corrupted data. A group of bots called checksum is added to each segment to determine the received segment with errors.

There are 2 protocols used in the Transport layer:

1. User Datagram Protocol: User Datagram Protocol uses a connectionless service. i.e. UDP delivers data packets without setting a predefined path; hence no session is established for connection. In UDP, the path depends on the traffic of the available path.
2. Transmission Control Protocol: Transmission Control Protocol uses a connection-oriented service. In a connection-oriented service, TCP decides a path data units are delivered via the decided path. When the TCP conversation is finished, the session is terminated.

Application layer

The unit of communication in the application layer is the message. It allows the user to access internet services. It is used by network applications that use the internet. Many protocols are defined in this layer to provide services like FTP for file transfer, HTTP or HTTPS for accessing www, i.e. World Wide Web, SMTP for electronic mail, TELNET for Virtual Terminals, etc.

TCP/IP Protocols

Below is the list of commonly used TCP/IP protocols:-

HTTP

HTTP stands for HyperText Transfer Protocol. HTTP establishes a connection between client and server for data transmission. It is a non-secure transmission. A client sends a request to the server through a web browser to view specified information. After receiving a request, the server sends specified information to the client.

HTTPS

HTPPS stands for HyperText Transfer Protocol Secure. HTTPS establishes a connection between the client and the server for data transmission. It is a secure transmission. The client mainly uses this HTTPS to send private information like credit card details, online transactions, etc., to the server across the internet connection.

FTP

FTP Stands for File Transfer Protocol. It uses TCP services to transfer files from one host to another. It establishes a connection between two hosts. After the connection is established, the host can send and receive data or files.

SMTP

SMTP stands for Simple Mail Transfer Protocol. It is a widely used and most important protocol used to transfer emails from sender to receiver. It is an application layer protocol, as we have seen previously. It is a Push protocol that is used to send an email. After that, POP post office protocol) or IMAP (internet message access protocol) protocols retrieve emails on the receiver end.

TELNET

TELNET stands for Terminal Network. It establishes the connection between the local computer and the remote computer so that the local terminal seems to be a terminal at the remote system.

FTP

FTP stands for File Transfer Protocol. It is an internet protocol used for transferring data, media files from one computer to another computer.

Advantages of TCP/IP

Below are some of the advantages explained.

• Provides scalability feature; this feature allows adding N number of networks without disturbing current services.
• It is interoperable, which means it allows two different systems to communicate over a heterogeneous network.
• It is open-source, i.e. free to use. Anyone can use it for communication.
• It is an industry-standard model which is developed to solve problems related to communication over a network.
• It assigns a unique IP address to each device across the network. So each device is identified uniquely over the network.

Conclusion

This article has seen what is TCP/IP, a detailed explanation of the layers in the TCP/IP and the advantages of using it over the network.

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