1) List the two major Transport layer protocols and describe what they do.

2) Explain why error correction is more important at the Transport layer than at the Data Link layer.

3) The Protocol Data Unit at the Data Link layer is the Frame. The PDU at the Network layer is the Packet. List the PDUs for TCP and UDP at the Transport layer. (The author listed the PDU for TCP incorrectly, so refer to the chapter notes for your answer).

4) Explain how and why we use sequence numbers in a TCP segment.

5) Consider two computers talking to each other, using TCP to send a series of segments. What happens if one computer sends a segment that gets lost?