Figure 3 illustrates how the TCP/IP services fit into the OSI model.
Figure 3: The OSI Model vs. the Internet Protocol Suite
The Network Interface layer corresponds to the Physical and Data Link layers of the OSI model. It is responsible for moving frames over the wire. The Internet layer corresponds to the Network layer of the OSI model. It is at this level that a packet is encapsulated into an Internet datagram. In addition, all routing algorithms are run at the Internet layer. The Transport layer is responsible for providing connection oriented and connectionless communication between two hosts. The application layer addresses applications such as Telnet, FTP, and SNMP.
This technical note will address the implementation details of the LM TCP/IP at the Internet and Transport layers.
Figure 4 illustrates how the protocols that are included with the LM TCP/IP fit into the layers as defined by the Internet Protocol Suite.
Figure 4: The LM TCP/IP implementation and the Internet Protocol Suite