Please Whitelist This Site?

I know everyone hates ads. But please understand that I am providing premium content for free that takes hundreds of hours of time to research and write. I don't want to go to a pay-only model like some sites, but when more and more people block ads, I end up working for free. And I have a family to support, just like you. :)

If you like The TCP/IP Guide, please consider the download version. It's priced very economically and you can read all of it in a convenient format without ads.

If you want to use this site for free, I'd be grateful if you could add the site to the whitelist for Adblock. To do so, just open the Adblock menu and select "Disable on tcpipguide.com". Or go to the Tools menu and select "Adblock Plus Preferences...". Then click "Add Filter..." at the bottom, and add this string: "@@||tcpipguide.com^$document". Then just click OK.

Thanks for your understanding!

Sincerely, Charles Kozierok
Author and Publisher, The TCP/IP Guide


NOTE: Using software to mass-download the site degrades the server and is prohibited.
If you want to read The TCP/IP Guide offline, please consider licensing it. Thank you.

The Book is Here... and Now On Sale!

Get The TCP/IP Guide for your own computer.
The TCP/IP Guide

Custom Search







Table Of Contents  The TCP/IP Guide
 9  TCP/IP Lower-Layer (Interface, Internet and Transport) Protocols (OSI Layers 2, 3 and 4)
      9  TCP/IP Transport Layer Protocols
           9  Transmission Control Protocol (TCP) and User Datagram Protocol (UDP)
                9  TCP/IP Transmission Control Protocol (TCP)

Previous Topic/Section
TCP Common Applications and Server Port Assignments
Previous Page
Pages in Current Topic/Section
1
Next Page
TCP Operational Overview and the TCP Finite State Machine (FSM)
Next Topic/Section

TCP Basic Operation: Connection Establishment, Management and Termination

While I have described the Transmission Control Protocol as connection-oriented, this term isn't "just any old characteristic" of TCP. The overall operation of the entire protocol can be described in terms of how TCP software prepares, negotiates, establishes, manages and terminates connections. TCP implementations certainly do more than handle connections, but the other major tasks they perform, such as data handling and providing reliability and flow control, can only occur over a stable connection. This makes connections the logical place to begin in exploring the details of how TCP does its thing.

In this section I describe TCP connections from start to finish. I begin with an overview of TCP's operation by providing a summary of the finite state machine that formally defines the stages of a connection. State machines can be a bit mind-boggling when you read about them in standards, but a simplified version provides an excellent high-level view of the "life" of a connection, so it is a good place to start.

From there, I move on to provide details about TCP's handling of connections. I described how connections are prepared and transmission control blocks (TCBs) set up, and the difference between a passive and an active socket open. I explain the three-way handshake used to create a connection, and the method by which parameters are exchanged and sequence numbers synchronized. I talk about how an established connection is managed, including the method by which TCP handles problem conditions and resets the connection when necessary. Finally, I describe how a connection can be terminated when it is no longer needed.

Background Information: The detailed topics in this section assume your familiarity with the concepts in the previous fundamentals section, especially the notion of sequence numbers.


Quick navigation to subsections and regular topics in this section



Previous Topic/Section
TCP Common Applications and Server Port Assignments
Previous Page
Pages in Current Topic/Section
1
Next Page
TCP Operational Overview and the TCP Finite State Machine (FSM)
Next Topic/Section

If you find The TCP/IP Guide useful, please consider making a small Paypal donation to help the site, using one of the buttons below. You can also donate a custom amount using the far right button (not less than $1 please, or PayPal gets most/all of your money!) In lieu of a larger donation, you may wish to consider purchasing a download license of The TCP/IP Guide. Thanks for your support!
Donate $2
Donate $5
Donate $10
Donate $20
Donate $30
Donate: $



Home - Table Of Contents - Contact Us

The TCP/IP Guide (http://www.TCPIPGuide.com)
Version 3.0 - Version Date: September 20, 2005

© Copyright 2001-2005 Charles M. Kozierok. All Rights Reserved.
Not responsible for any loss resulting from the use of this site.