Basics of IP Layers | TCP/IP

 

TCP/IP is an abbreviation for transmission control protocol / internet protocol. TCP/IP is a collection of protocols, applications and services. The protocols in TCP/IP that defines how two or more computer or devices can communicate with each other. The protocols is effectively a set of rules how data is passed between the computers or devices.  TCP/IP moves data from one layer to another.

 

OSI Layer model has 7 Layers but in TCP/IP those 7 layers are approximately mapped with its 4 Layers. In some cases TCP/IP models considers as 5 Layers.

OSI Model (7 Layer)	TCP/IP Model (4 Layer)	TCP/IP Model (5 Layer)
Application
Presentation	Application	Application
Session		TCP or UDP
Transport	Transport
Network	Network	IP
Data Link		Network Interface
Physical	Physical	Physical

 

Physical Layer: The Physical Layer is pure hardware in any network infrastructure. This includes the cables, satellites or any other connection medium and the network interface card, which transmits electrical signals. It describes the media over which the data travels. For example, this describes the voltage of a 1 or 0 signal across a copper wire.

Data Link Layer: This layer is responsible for splitting data into packets to be sent across the connection medium. Once the data is on the communication link, the layer handles any interferences, which may arise due to noise. The data link layer works hard to make sure that the physical link does not distort the electrical signals carrying the data.

 

Network Layer: This layer gets packets from data link layer and sends them to correct network address. This layer routed the packet through the best possible route if more than one possible route available in the network.

Transport Layer: The packets routed by network layer to the destination, it cannot guarantee that the data packets will arrive in correct order. The packets may have picked up any errors during transmission. Transport layer takes care of that the packets have no errors and received in correct order.

Application Layer: Users uses the application layer to send or receive data. These provides the interface to the application. Without this layer the computer or its user would never be able to send data and would not know what to do with the received data send by another user.