TCP/IP (Transmission Control Protocol) Reference Model | What is TCP/IP Model | Layers of TCP/IP Model.

What is TCP/IP Reference Model

TCP/IP stands for Transmission Control Protocol and its a internet protocol. Current internet architecture as well following this model. Protocols in TCP/IP describe the movement of data from source to destination in a network.

TCP/IP developed by DARPA (Department of Defence's Project Research Agency). The idea behind TCP/IP model is that the data can be transmit from one computer to another computer in a network or from one application to another application.

Layers of TCP/IP Model

TCP/IP Model has four layers as following.

1. Network Interface Layer

TCP/IP model lowest and 1st layer is Network Interface Layer. This layer also called as Host-To-Network layer and Network Access Layer of  TCP/IP Model. This layer is designed to transmit packets in network and to receive packets from a network. 

TCP/IP can be used to connect different network types, either it s ethernet LAN technology or WAN technology such as x.25 and frame relay.

2. Internet Layer

The internet layer is responsible for the addressing, packaging and routing of the data. This layer responsible of the routing network that how data will transmit from source to destination. The protocols of internet layers are IP, ARP, ICMP, IGMP. 

• This is the layer which holds the internet architecture independently. 

• The IP (Internet Protocol) is responsible for addressing of data and the routing as well from source to destination.

• The ARP (Address Resolution Protocol) is responsible for maintain the hardware address in a network.

• ICMP (Internet Control Message Protocol) provide the facility to diagnose the network issues happening in a network.

• IGMP (Internet Group Management Protocol) is responsible for the management of the multicast groups.

The internet layer of TCP/IP model is similar as the Network Layer of an OSI Model.

3. Transport Layer.

The Transport layer of TCP/IP model decides the transmission of data from source to destination. Basically its decides the that the transmission of data should be parallel or single path. Multiplexing, segmenting or splitting on the data is done by transport layer. Transport layer also add the header information of the data. This layer maintains the sequence of data sending from source to destination.

The Protocols used by the transport layer are TCP (Transmission Control Protocol) and UDP (User Datagram Protocol)

• TCP is a connection oriented protocol and used for the reliable communication in a network. Once the packet sent in a network its wait for the delivery acknowledgement and then transmit the another packet.

• UDP (User Datagram Protocol) is totally different from the TCP. Its send packets continuously without any acknowledgement of the previous packets.

4. Application Layer

The application Layer provides the ability to access the services of other layer that application use to exchange information or data. There are lots of application layer protocols and some of the protocols are being developed. Some of them are TELNET, FTP, SMTP, DNS etc.

• Telnet is used to access the remote machine and run applications on it.

• FTP (File Transfer Protocol) can be used to upload file on the remote application in a network.

• SMTP (Simple Mail Transport Protocol) is used to transfer emails from source to destination.

• DNS (Domain Name Service) Resolve the FQDN (Fully Qualified Domain) into IP address and vice versa.