TCP/IP First-Step [Electronic resources] نسخه متنی

Chapter 8. Guaranteed Delivery: Your Package Will Get Delivered…Eventually!

What You Will Learn

After reading this chapter, you should be able to answer the following questions:

What are the various stages of a communications session?

How does TCP regulate the flow of information between a source and destination machine?

What is a three-way handshake and what is its purpose?

What are the three uses for TCP sequence numbers?

What is a session?

How does a source computer tell a destination computer that the session is over?

What are the four special types of TCP packets that do not carry any application data?

What is a datagram?

At the risk of sounding like a commercial for a package delivery service, when it absolutely, positively, has to get there, use TCP/IP for your IP packet delivery needs. It is the mechanism for consistent and reliable information delivery. Although the technical community uses the term TCP/IP to generically describe the entire family of protocols, this chapter focuses on just the component known as TCP. The fact that TCP must use IP might lead to the confusing notion that TCP/IP can refer to both the entire family of protocolsspecifically to the combination of TCP and IP working together to guarantee delivery of data.

This chapter helps you better understand the concept of reliability, as well as show you how TCP/IP delivers on that promise. You walk through the various stages of a communications session. You even see how TCP handles some unusual situations or error conditions during a communications session. Lastly, you see how TCP's various mechanisms work to guarantee delivery of data.