Question

A network engineer is analyzing how data is processed as it moves down the OSI stack on a sending host. An application generates data, which is passed to the Transport layer where a TCP header containing source and destination port numbers is added. What is the correct term for this Transport layer PDU, and what is added at the very next layer down?

Accepted Answer

The PDU is a segment; the Network layer then adds a logical (IP) address header, creating a packet.

Answer

The PDU is a frame; the Data Link layer then adds a MAC address header, creating a packet.

Answer

The PDU is a packet; the Network layer then adds a port number header, creating a segment.

Answer

The PDU is a datagram; the Physical layer then adds a MAC address header, creating a frame.