top of page

TCP/IP - Internet Protocol Suite

Writer's picture: Ankita SharmaAnkita Sharma

Updated: Jan 23

Millions of people surf the #internet every day without even realizing how computers actually communicate over the network. The Internet Service Provider( #ISP ) provides internet services and connectivity by using some set of protocols to connect two or more computers and transmit data between them.


Internet Service Provider
Internet Service Provider

#TCP/IP ( Transmission Control Protocol / Internet Protocol ) is the most commonly used protocol on the web. The TCP/IP was designed and developed by the US Department of Defense ( DoD ) in the 1960s. It was originally designed for Unix Operating Systems, now it is compatible with all Operating Systems. The TCP/IP model and its protocols are maintained by the Internet Engineering Task Force ( #IETF ).




What is TCP/IP?


TCP/IP model is basically a set of communication #protocols that allow computers to communicate on the internet. IP obtains the address to which the data was sent while TCP delivers data after getting the #IP address. For getting a better idea, let us take an example - an IP address is just like mobile numbers for your mobile phones while TCP is all the technology that makes the phone ring, and enables you to talk to the person on another side of the phone. Although, they are different, but also meaningless without each other.


How TCP/IP Works?


The TCP/IP model breaks each message into packets, and then those packets are assembled back on the other end. It determines the most efficient path through the network. Also, it divides the communication task into four #layers. Firstly data goes through these four layers before it is received on another end and then it goes in reverse order to reassemble the data to present it to the recipient.



Layers of the TCP/IP model


The following are the four layers of the TCP/IP model -

  1. Application Layer

  2. Transport Layer

  3. Internet Layer

  4. Link Layer

Layers of TCP/IP model
Layers of TCP/IP model

Link Layer / Network Access Layer :


This layer is the combination of the link layer and physical layer of the #OSI model which defines how the data should be sent through the network. It also handles the physical parts of sending and receiving data using Ethernet cable, token ring, FDDI, frame relay, etc.


Internet Layer :


Its main responsibilities include controlling and sending data packets around the #network. The three main protocols residing in this layer are as follows -

  1. IP ( Internet Protocol ): This protocol is responsible for transmitting the data packets from source to destination based on the IP address in the packet headers. IP has two versions - IPv4 and IPv6.

  2. ICMP ( Internet Control Message Protocol ): This protocol is encapsulated within IP datagrams and provides hosts with information about network problems.

  3. ARP ( Address Resolution Protocol ): This protocol is responsible for finding the hardware address of a host from a known IP address.



Transport Layer / Host-to-Host Layer :


The main responsibility of the transport layer is to provide a reliable data connection between two devices. It divides the data into #packets and checks whether the devices have acknowledged the packet it has received. It also protects the upper-layer applications from the complexities of data.


Application Layer :


The application layer, also known as #Process Layer is the topmost layer in the TCP/IP model which is responsible for handling high-level protocols. It mainly allows the user to interact with the application. Following are some of the main protocols that are used in the Application layer -

  1. HTTP ( HyperText Transfer Protocol ): It allows the user to access data over the World Wide Web ( #WWW ).

  2. SNMP: SNMP stands for Simple Network Management Protocol. It manages the devices on the internet by using the TCP/IP protocol suite.

  3. SMTP: SMTP stands for Simple Mail Transfer Protocol. It allows the user to send the data to another email address.

  4. FTP: FTP stands for File Transfer Protocol. They are used to transmit the files from one computer to another computer.

  5. TELNET: #TELNET is an abbreviation for Terminal Network. It provides a command-line interface for communication with a remote device or server.

Basically, the TCP/IP model is a more practical and concise version of the OSI model.




TCP/IP Model v/s OSI Model :


OSI ( Open System Interconnection ) is a conceptual model based on functionalities of each layer that basically deals with how the communication needs to be done whereas the TCP/IP model is a protocol-oriented standard on which the internet was developed.

  1. TCP/IP model consists of four layers while the OSI model consists of seven layers.

  2. TCP/IP uses both the session and presentation layers in one layer ( i.e. Application Layer). While OSI uses different session and presentation layers.

  3. TCP/IP is more reliable as compared to the OSI model.

OSI v/s TCP/IP