By: Adam Eisner

May 14th, 2001

Reader Rating: 8

When choosing a host, the amount of bandwidth you purchase can be crucial to the success of your site. Generally speaking, the more bandwidth you have, the more traffic your site will be able to handle at one time.

How much bandwidth do I need?

To determine how much bandwidth you’ll need, you must first:

• estimate how big each page on your site is, and
• how many people are going to view it.

To do this, add up the size of every image on the page and the size of the page's HTML files. Then multiply this figure by the number of views you expect for that page per month.

For example, if you had three 10k images on your page and a 2k HTML file, you would have 32k of data on that page. Multiply that by your expected page views (let's say 100,000 per month), and you get 3.2G of data to be transferred that month for that page.

Now recalculate this number for each page, and you’ll know approximately how much bandwidth your entire site requires.

How can I save bandwidth?

There are three key ways to optimize your bandwidth usage:

1. Keep your pages as small as possible.
This means tight HTML programming to reduce file size, and compacting your pictures and graphics to reduce image size (NetMechanic [1] has a free, easy-to-use file compression utility). Use the JPEG image format for your photos and the GIF format for graphics - their compression abilities are second to none.

Dr. HTML's site [2] has useful tools that will analyze your site's image sizes, transfer amounts, table structure and more.

2. Use images that aren’t stored on your site.
You can do this by replacing the file name in your <IMG SRC> tag with a URL that gives the location of the image you want to use. Before doing this, however, make sure you have the permission of the site you are linking to. Otherwise, you’re stealing bandwidth, which is considered pirating and is therefore illegal (for more information, see “How can I prevent bandwidth theft?” below).

3. Use Cascading Style Sheets (CSS).
Another effective way to save bandwidth is to use CSS. Designed to reduce HTML file size, CSS attribute values for any HTML element/command at the beginning of the document, rather than repeating them throughout.

For more information on CSS and other resources related to bandwidth conservation, visit Infohiway [3] or the SitePoint CSS Tutorial. [4]

How can I prevent bandwidth theft?

To use another site’s images by linking to them through your <IMG SRC> tags without permission is a form of double piracy: you’re pirating both the site's image and its bandwidth. As unethical as it may be, it’s a reality many webmasters have to deal with on a daily basis.

Policing
The most basic method of preventing theft of your bandwidth is policing. Analyze search engines, logs, and other sites to find out who’s using your images (and your bandwidth) without permission.

Once you've identified the offenders, you can contact them and order them to stop linking to your site (and if they try to feed you a story about everything on the Internet being in the "public domain," don't buy it). Unfortunately, policing sites yourself is a time-consuming task.

Commercial Software
A more costly but time-efficient way to protect your bandwidth is to take advantage of the software packages that are currently available.

A standard log analysis program like WebTrends [5] can help track bandwidth thieves, as most software suites like this will identify the most popular referrers and visitors to your site. Armed with that information, you can work backward to find out if any sites are hitching a ride on your connection. Most Web hosts offer some sort of log analysis program as a standard feature of their hosting package.

If you're looking for something a bit more automated, Artistscope [6] offers a number of utilities that can protect your images through encryption, secure Web hosting, and other methods. Protection plans start as low as $US10 per 100 page views.

Or, for an extremely secure, high-end solution, Digimarc [7] has developed patented digital technology that embeds a "watermark" on all files, providing copyright protection and tracking for your electronic property.

Where can I find out more?

For further details on bandwidth, take a look at Bandwidth.com [8], a site that matches users with bandwidth providers. About.com [9] recently launched a bandwidth-specific Web site that's chock-full of bandwidth-related news and information. And be sure to visit MSN's message board community [10], where you'll find an entire section dedicated to connectivity.

[1] http://www.netmechanic.com
[2] http://www2.imagiware.com/RxHTML/
[3] http://www.infohiway.com/faster/
[4] http://www.webmasterbase.com/article.php/309
[5] http://www.webtrends.com/redirect/14ASJP.htm
[6] http://www.artistscope.net
[7] http://www.digimarc.com
[8] http://www.bandwidth.com
[9] http://bandwidth.about.com
[10] http://computingcentral.msn.com/AllMessageBoards/