It is to provide the communication services directly to the application processes running on different hosts.

The transport layer transmits the entire message to the destination.

• End-to-end delivery

• Addressing

• Reliable delivery

• Flow control

It is used to prevent the sender from overwhelming the receiver. If the receiver is overloaded with too much data, then the receiver discards the packets and asking for the retransmission of packets.

• End-to-end delivery

• Addressing

• Reliable delivery

• Flow control

The transport layer uses the multiplexing to improve transmission efficiency.

• End-to-end delivery

• Addressing

• Reliable delivery

• Multiplexing

According to the layered model, the transport layer interacts with the functions of the session layer.

• End-to-end delivery

• Addressing

• Reliable delivery

• Multiplexing

The transport layer provides reliability services by retransmitting the lost and damaged packets.

• End-to-end delivery

• Addressing

• Reliable delivery

• Multiplexing

simple protocol and it provides nonsequenced transport functionality.

The closest layer to the end user which means that the application layer and end user can interact directly with the software application. The application layer programs are based on client and servers.

• Application Layer

• Network Virtual terminal

• Addressing

• Mail Services

Fixed and provides a set of services to applications.

• Network architecture

• Architecture

• Client-server

• P2P (peer-to-peer) architecture:

a program that runs on the local machine requesting service from the server.