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!

Searchable, convenient, complete TCP/IP information.
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

Previous Topic/Section
TCP/IP Transport Layer Protocols
Previous Page
Pages in Current Topic/Section
1
Next Page
TCP and UDP Overview and Role In TCP/IP
Next Topic/Section

Transmission Control Protocol (TCP) and User Datagram Protocol (UDP)

TCP/IP is the most important internetworking protocol suite in the world; it is the basis for the Internet, and the “language” spoken by the vast majority of the world's networked computers. TCP/IP includes a large set of protocols that operate at the network layer and above. The suite as a whole is anchored at layer three by the Internet Protocol (IP), which many people consider the single most important protocol in the world of networking.

Of course, there's a bit of architectural distance between the network layer and the applications that run at the layers well above. While IP is the protocol that performs the bulk of the functions needed to make an internetwork, it does not include many capabilities that are needed by applications. In TCP/IP these tasks are performed by a pair of protocols that operate at the transport layer: the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP).

Of these two, TCP gets by far the most attention. It is the transport layer protocol that is most often associated with TCP/IP, and, well, its name is right there, “up in lights”. It is also the transport protocol used for many of the Internet's most popular applications, while UDP gets second billing. However, TCP and UDP are really peers that play the same role in TCP/IP. They function very differently and provide different benefits and drawbacks to the applications that use them, which makes them both important to the protocol suite as a whole. The two protocols also have certain areas of similarity, which makes it most efficient that I describe them in the same overall section, highlighting where they share characteristics and methods of operation, as well as where they diverge.

In this section I provide a detailed examination of the two TCP/IP transport layer protocols: the Transmission Control Protocol (TCP) and the User Datagram Protocol (UDP). I begin with a quick overview of the role of these two protocols in the TCP/IP protocol suite, and a discussion of why they are both important. I describe the method that both protocols employ for addressing, using transport-layer ports and sockets. I then have two detailed sections for each of UDP and TCP. I conclude with a summary quick-glance comparison of the two.

Incidentally, I describe UDP before TCP for a simple reason: it is simpler. UDP operates more like a classical message-based protocol, and in fact is more similar to IP itself than is TCP. This is the same reason why the section on TCP is much larger than that covering UDP: TCP much more complex and does a great deal more than UDP.

Quick navigation to subsections and regular topics in this section



Previous Topic/Section
TCP/IP Transport Layer Protocols
Previous Page
Pages in Current Topic/Section
1
Next Page
TCP and UDP Overview and Role In TCP/IP
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.