Packet segmentation

In data networks, packet segmentation is the process of dividing a data packet into smaller units for transmission over a network. Packet segmentation occurs at the fourth level of the OSI model - the transport layer ^[1] . Segmentation may be required if:

• the data packet is larger than the maximum transmission unit supported by the network;
• the network is unreliable, and it is desirable to divide the information into smaller segments in order to maximize the likelihood that each of them can be delivered correctly to the addressee .

Protocols that perform packet segmentation on the sender side typically contain a mechanism to reverse the process and assemble the source packet from separate segments on the destination side. This process may include automatic retransmission requests (ARQs) to detect missing segments and requests to the recipient to resend specific segments.

In a communication system based on the multi - level OSI model , packet segmentation may be responsible for dividing one MPDU into several physical layer service data units to ensure reliable transmission (and possible retransmission via ARQ) of each of them individually.

The ITU-T G.hn standard, which provides a way to create a high-speed (up to 1 gigabit / s) local area network using existing home wiring ( power lines , telephone lines and coaxial cables ), is an example of a protocol that uses packet segmentation to increase reliability in susceptible environments.