There are two types of transport layer protocols: connection-oriented and connectionless. Connection-oriented protocols guarantee the delivery of datagrams from source to destination by creating a connection between the sender and receiver before any data is transmitted. Connectionless protocols do not require a connection between end systems in order to pass datagrams. The physical layer does not use connectionless or connection-oriented protocols; it defines standards for transmitting and receiving information over a network.
The network layer is responsible for logical addressing and routing. The session layer is responsible for creating and maintaining a dialog between end systems. The presentation layer is responsible for the formatting, translation, and presentation of information.