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 TCP/IP Guide  9  Networking Fundamentals       9  Network Performance Issues and Concepts

Balancing Network Performance with Key Non-Performance Characteristics 1 2 3 Understanding Performance Measurement Units

Applying Performance Measurement Terms

As with all networking terms, there are no hard and fast rules; many people are rather loose with their use of the terms above. You will even see terms such as “throughput bandwidth”, “bandwidth throughput” and other charming inventions from the department of redundancy department. J More often, you will just see a lot of mish-mashed term usage, and especially, spurious conclusions being drawn about what data streams a network can handle based on its rated speed. Making matters worse is that speed ratings are usually specified in bits per second, but throughput may be given in bits or bytes per second.

In general, “speed”, bandwidth and throughput get a lot of attention, while latency gets little. Yet latency considerations are very important for many real-time applications such as streaming audio and video and interactive gaming. In fact, they are often more important than raw bandwidth.

For example, suppose you move to a rural home and your choices for Internet access are a regular 28.8 kbps modem connection or fancy satellite Internet. The companies selling satellite connectivity call it “broadband” and advertise very high rated speeds—400 kbps or more. They make a big deal about it being “over 10 times as fast as dialup” and they certainly charge a lot for this very high-tech service. This is a slam dunk, right?

Wrong. The satellite connection has high bandwidth, but very poor (high) latency due to the time it takes for the signals to travel to and from the satellite. It is definitely much better than the modem for downloading that nice little 150 MB patch from Microsoft. However, it is much worse than the modem for playing the latest online video game with your buddy over the Internet, because of the latency, or lag, in transmissions. Every move you make in your game will be delayed for over half a second as the signal bounces around between the satellite and the earth, making online gaming nearly impossible. Thus, whether satellite Internet is worth the extra money depends entirely on what you plan to use it for.

Balancing Network Performance with Key Non-Performance Characteristics 1 2 3 Understanding Performance Measurement Units