What is Internet Protocol Suite : Architecture & Its Layers

An Internet Protocol Suite is invented by Vint Cerf and Bob Kahn in the year 1970. In 1973 TCP was divided into two protocols that are TCP (Transmission Control Protocol) and IP (Internet Protocol). In the year 1983, the NCP that is Network Control Protocol was replaced by an Internet protocol suite. In 1992 the work began on Internet Protocol next generation (IPng) and the IPng became IPV6 and IPV4. An IPV6 attempted to fix some of the inherent issues in the internet protocol. The transmission control protocol includes both IPV6 and the IPV4 set of protocols, and these both are the internet layers of TCP/IP protocol suite. The packet size of IPV6 is 1280 bytes and the IPV4 packet size is 576 bytes.

What is Internet Protocol Suite?

The Internet Protocol Suite is also known as a TCP/IP protocol suite or TCP/IP model. It is one type of protocol and network model used on the internet. It consists of four layers’ application layer, transport layer, internet layer, and the link layer. In this networking, the TCP and the IP layers are the most widely used protocols, so that this model named as TCP/IP model or Internet Protocol Suite model. The key architecture principles are discussed below.

Let us take two hosts one is a client and another is a server. For example, the client has opened a webpage that is having some services and in the next step, the client wants to upload records or data or files. Whenever the client wants to upload or update the record that the request goes to the server. Suppose the client or user wants to change the settings of an email, then the settings will reach to the server. This can be done using the TCP/IP model and this process goes to the transport layer and reaches the network. The Transport layer act as a host of the system and the process reaches to the network with the help of cables. The internet protocol suite architecture is shown in the below figure.


The cable is a physical cable we can call it as a media. The data goes from one cable to another cable with the help of the link layer. The connection between two networks is the internet layer and that layer uses LAN, WAN, and MAN and all these layers are applicable. The connection between the hosts of the client and server is transport layer and this layer is OS independent or computer architectures are independent and finally the updated site opened on the server-side. The communication between the client and server process is the application layer, we can call it a client-server model.

Internet Protocol Suite Layers

The TCP/IP model classified into two types they are four-layer TCP/IP model and five TCP/IP models. The layer numbers start from the bottom and go up. The classification of the TCP/IP model shown in the below figure


  1. Four Layer TCP/IP Model: The four-layer TCP/IP model consists of four layers are Application layer, Transport layer, Internet layer, and link layer. The layer number, layer name, and protocol name are shown in the below table.

Layer Number Layer Name Protocol Name
4. Application Layer HTTP, Telnet, DNS, SNMP, DHCP
3. Transport Layer TCP, UDP
2. Internet Layer IP, ICMP, IGMP
1. Link Layer Ethernet, Wireless LAN, PPP, ARP

  a) Application Layer: It is the fourth layer in the TCP/IP model. The application layer has a wide variety of application protocols. Some examples of application protocols are HTTP, Telnet, DNS, SNMP, and DHCP.

  • HTTP: The standard form of HTTP is the HyperText Transfer Protocol, which provides the World Wide Web (WWW.Com) services.
  • Telnet: The Telnet is used for remote access for a computer.
  • DNS: The standard form of the DNS is the Domain Name System, it is a distributed service that used for translate domain names and IP addresses.
  • SNMP: The standard form of SNP is the Simple Network Management Protocol. It is used for managing network devices locally or remotely.
  • DHCP: The standard form of DHCP is the Dynamic Host Configuration Protocol, which is used for automating the configuration network interfaces.

  b) Transport Layer: It is the third layer in the TCP/IP model, which provides transport facilities for the application layer. Here you can remember the concept that each higher layer uses the services provided by the lower layers. The transport layer as two protocols are TCP and UDP.

  • TCP: The standard form of TCP is Transmission Control Protocol, it provides reliable data transmission over an IP network and this protocol is connection-oriented.
  • UDP: The standard form of UDP is User Datagram Protocol, it is a connectionless protocol used to provide any reliability guarantee because of its simplicity than the TCP. This protocol is widely used in real-time communications and DNS services.

  c) Internet Layer: It is the second layer in the TCP/IP model, which is used for routing the packets across the internet and this layer has an Internet Protocol. IP protocol is connectionless and provides unreliable services, that’s why we use two more protocols for control and management purposes. Here you need to understand one thing, we have two connections when we talk about networking they are control connection and data connection. Data connection carries the data and control connection provides the control and management services for that particular network. Here IP is used for data connection and ICMP & IGMP used for the control connection. An ICMP & IGMP are both used for control and management purposes, they don’t involve actual data communications.

  d) Link Layer: The link-layer used to handle all hardware and provides data transmission for the network layer. There are some technologies and protocols in this layer they are Ethernet, Wireless LAN, PPP, and ARP.

  • Ethernet: The Ethernet provides multiple access to the LAN (Local Area Network).
  • Wireless LAN: The Wireless LAN provides multiple wireless access to the Local Area Network (LAN) based on IEEE 802 standard. The IEEE 802 is very famous standard when you purchase a new mobile or new laptop you can see this protocol on that particular device.
  • PPP: The standard form of PPP is Pint to Point Protocol, which is used to connect the pair of hosts.
  • ARP: The standard form of ARP is Address Resolution Protocol. It is responsible for resolving new layer addresses.

There is a problem in the link layer that is, In the link layer we have Ethernet and Wireless LAN which are actual hardware technologies and PPP, ARP is the real-time protocols which is software related concept. So here is the problem that is most confusing among the network vendors because some vendors are only making hardware and some vendors are only making software. So how can we encounter this situation?

 2) Five Layer TCP/IP model: The solution of this link layer is to divide the link layer into two different layers. The data link layer and the physical layer are two layers and this is how the five-layer TCP/IP model is made. Now a day’s in the industry level all the people are using the five-layer TCP/IP model.

Layer Number Layer Name Protocol Name
5. Application Layer HTTP, Telnet, DNS, SNMP, DHCP
4. Transport Layer TCP, UDP
3. Network Layer IP, ICMP, IGMP
2. Datalink Layer LAN, PPP, ARP
1. Physical Layer Ethernet, Wireless

The five-layer TCP/IP protocol has five layers they are Application Layer, Transport Layer, Network Layer, Datalink Layer, and Physical Layer. The Physical Layer is the first layer which is mainly focused on hardware like Ethernet and wireless LAN, the second layer is Datalink Layer which is mainly focused on the software portion like PPP and ARP, the third layer is Network Layer, the fourth layer is Transport Layer, and the fifth layer is Application Layer. In the four-layer TCP/IP model, we have an internet layer and in the five-layer TCP/IP model we have a network layer, both layers have the same sort of functionality.


The advantages of the internet protocol suite include the following.

  • Scalable
  • Interoperable
  • Easy to understand
  • Stability
  • Reliability
  • Availability of public IP’s are limited

The Internet Protocol Suite classification, advantages, architecture are discussed in this article. Here is a question for you total how many protocols are used in the Internet Protocol Suite?