OSI layering and packet structure
The network protocol stack (TCP/IP and similar protocol stacks) evolved to make it possible for various applications running on various computers to send and receive data from each other. Over time, each layer in the protocol stack was developed to take care of certain aspects of this data transfer. For example, one layer ensures the reliability and consistency of transferred data, while another layer makes sure that the data traverses from the source computer to the destination computer (addressing aspect). The TCP/IP protocol stack was created gradually by developing various protocol layers that served specific purposes.
The Open Systems Interconnection (OSI) layering model describes how a message is encapsulated with various headers – corresponding to the various (seven) layers – for communicating between two systems over the internet. The seven layers described in the OSI model include the physical layer, the data link layer, the...
