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!

Enjoy The TCP/IP Guide? Get the complete PDF!
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)

Previous Topic/Section
UDP Common Applications and Server Port Assignments
Previous Page
Pages in Current Topic/Section
1
Next Page
TCP Overview, Functions and Characteristics
Next Topic/Section

TCP/IP Transmission Control Protocol (TCP)

In my description of the Internet Protocol, I call it the “workhorse” of the TCP/IP protocol suite. IP is, in fact, the foundation upon which the other protocols of the suite are built. Well, if IP is the “workhorse”, then the “worker” that rides on that horse would have to be the TCP/IP Transmission Control Protocol (TCP). Like horse and rider, TCP and IP form a team that work together to make it possible for applications to easily run over an internetwork.

TCP and IP share the marquee in the name of the suite, and are very important complements to each other. IP concerns itself with classic network-layer tasks such as addressing, datagram packaging and routing, which provide basic internetworking capabilities. TCP provides to applications a method of easily making use of IP, while filling in the capabilities that IP lacks. It allows TCP/IP devices to establish and manage connections and send data reliably, and takes care of handling all the potential “gotchas” that can occur during transmission so each application doesn't need to worry about such matters. To applications, TCP could thus be considered almost like a nice user interface to the fairly rudimentary capabilities of IP.

This section provides a comprehensive description of the concepts, characteristics and functions of the Transmission Control Protocol (TCP). TCP is a rather complex protocol that includes a number of sophisticated functions to ensure that applications function in the potentially difficult environment of a large internetwork. It's also, as I said above, a very important part of the TCP/IP protocol suite. For this reason, the section is rather large, and has been divided into five subsections.

The first subsection provides an overview of TCP, describing its history, what it does and how it works. The second paints some important background information that is necessary to understanding how TCP operates. This is done by explaining key concepts such as streams and segments, sliding windows and TCP ports and connections. The third subsection describes the process used by TCP to establish, maintain and terminate sessions. The fourth describes TCP messages, and how they are formatted and transferred. Finally, the last subsection shows how TCP provides reliability and other important transport layer functions to applications, such as flow control, retransmission of lost data and congestion avoidance.

Background Information: Since TCP is built on top of IP, in describing TCP, I make the assumption that the reader has at least a basic familiarity with IP. If you have come to this section without first gaining an understanding of IP, I'd suggest reading that section first. Since it's large, reviewing the portion describing IP concepts will likely suffice for background.


Quick navigation to subsections and regular topics in this section



Previous Topic/Section
UDP Common Applications and Server Port Assignments
Previous Page
Pages in Current Topic/Section
1
Next Page
TCP Overview, Functions and Characteristics
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.