Key Terms

Review the following list of key terms:

• Application layer— The layer of the TCP/IP stack that supports network applications and provides an interface to the local operating environment.

• Datagram— The data package passed from the Internet layer to the Network Access layer, or a data package passed from UDP at the Transport layer to the Internet layer.

• Frame— The data package created at the Network Access layer.

• Header— A bundle of protocol information attached to the data at each layer of the protocol stack.

• Internet layer— The layer of the TCP/IP stack that provides logical addressing and routing.

• IP (Internet Protocol)— The Internet layer protocol that provides logical addressing and routing capabilities.

• Message— In TCP/IP networking, a message is the data package passed from the Application layer to the Transport layer. The term is also used generically to describe a message from one entity to another on the network. The term doesn’t always refer to an Application layer data package.

• Network Access layer— The layer of the TCP/IP stack that provides an interface with the physical network.

• Segment— The data package passed from TCP at the Transport layer to the Internet layer.

• TCP (Transmission Control Protocol)— A reliable, connection-oriented protocol of the Transport layer.

• Transport layer— The layer of the TCP/IP stack that provides error control and acknowledgment and serves as an interface for network applications.

• UDP (User Datagram Protocol)— An unreliable, connectionless protocol of the Transport layer.