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View Full Version : Bandwidth là gì ? làm thế nào để tiết kiệm bandwidth



vietfirm.com
07-11-2002, 09:42
Introduction to Bandwidth


When choosing a host, the amount of bandwidth you choose to purchase can be crucial to the success of your site. Generally speaking, the more amount of 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 will need, you must 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, and multiply that by the amount of views for that page you expect 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 in this case it is 100,000 per month), and you get 3.2 G of data to be transferred that month for that page. Now calculate this for each page, and you will know approximately how much bandwidth your entire site requires.

How can I save bandwidth?

There are a number of ways to optimize your bandwidth usage. First and foremost, keep your pages small as possible. This means tight HTML programming to reduce file size, and compacting your pictures and graphics to reduce image size (NetMechanic has a free, easy-to- use file compression utility). Use the JPEG image format for your photos and the GIF format for graphics, as their compression abilities are second to none.

Take a look at Dr. HTML's site for some useful tools that will analyze your site's image sizes, transfer amounts, table structure and more.

Another way to save bandwidth is to use photos and images on your site that are actually stored elsewhere. You can do this by replacing the file name in your IMG SRC tag with a URL. Before doing this, however, make sure you have the permission of the site you are linking to. Otherwise, you are "stealing bandwidth", which is considered pirating and is therefore illegal (for more information, see "preventing bandwidth theft" below).

Cascading Style Sheets (CSS) is also an effective way to save bandwidth. It is designed to reduce HTML file size by attributing values for any HTML element/command at the beginning of the document.

For more information on CSS and other resources related to bandwidth, visit Infohiway's site on bandwidth conservation.

Preventing bandwidth theft

Using another site's images by linking to them in your IMG SRC tag without permission means is a form of double piracy; that is, you are pirating both the site's image and bandwidth. As unethical as it may be, it is a reality many webmasters have to deal with on a daily basis.

The most basic method of preventing bandwidth theft is policing. This entails analyzing search engines, logs and other sites to find out who is using your images (and therefore your bandwidth) without permission. Once you have located the offending party/parties, you can contact them and order them to stop linking to your site (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.

Another more costly but time-efficient way to protect your bandwidth and images is through commercial software. Artistscope offers a number of utilities that can protect your images through encryption and other methods.

Other resources

If you still have questions, take a look at Bandwidth.com, a site that matches users with bandwidth providers. Also be sure to visit Microsoft's Bandwidth forum for more resources.