Bandwidth Basics: Definition and Management Tips

Bandwidth Definition
Bandwidth is a measurement of data transfer rate expressed as a unit of digital information divided by a unit of time, such as 200 bits per second (a bit is a single digit — either a 0 or a 1 — in binary code). If you own an ecommerce business, the data for the front and back ends of your shopping cart must be stored (hosted) on a server. As you and your customers request specific pages associated with your site, the server transmits the data to your web browsers; this data transfer consumes bandwidth. It is vital to remember that a server’s bandwidth capacity is dictated by the physical properties of its network connection cables (think of them as water lines, which cannot pump water beyond a specific maximum rate). This means that bandwidth is a finite — and valuable — resource. When a server receives more requests than it can fulfill at once, it must slow down, delay, or deny some requests. And, yes, even hosting that offers “unlimited” bandwidth is not exempt from these basic limitations.

Since most hosting companies assign multiple clients to a single server, any individual client’s bandwidth consumption can affect all other clients sharing the server (think of water pressure dropping when too many faucets try to draw from the same water line at once). Therefore, the hosting company must allocate a certain acceptable amount of the server’s total bandwidth capacity to each client, usually a monthly rate specification. This allocation is based on the client’s level of financial commitment, which in turn is based on the client’s anticipated needs. If you use more than this agreed-upon bandwidth allotment, you can expect to pay overage fees.

Here are some conversions that will help you anticipate how much bandwidth you can expect your site to consume:
1 Byte = 8 bits
1 KB = 1024 Bytes
1 MB = 1024 KB (1,048,576 Bytes)
1 GB = 1024 MB (1,048,576 KB / 1,073,741,824 Bytes)

Bandwidth Management
If your site is a bandwidth guzzler, keep four factors in mind: file size, number of files per page, pages viewed per visit, and monthly number of visits. While reducing the value of any one of these factors can reduce total bandwidth consumption, some are easier (and more desirable) to control than others. Obviously you want lots of visits, but you don’t necessarily want each visitor loading tons of images and graphics, especially if the file sizes are large. You can always reduce the number of image files on any given page, and you can always resize the ones you choose to keep with a program like Photoshop. If your site offers file downloads, a compression tool will help alleviate excessive bandwidth usage. If you use JavaScript, call it up externally whenever possible rather than embedding it within each page. And if you’re thinking of including audio, video, or large flash files, ask yourself if they’re necessary. They may very well end up costing you more money than they bring in.

Happy Selling!
-David Yakubik, Volusion

2 Responses to “Bandwidth Basics: Definition and Management Tips”

  1. Huw Roberts

    YourZoom offers a bandwidth-optimized image viewer to help you show off the detail of your products. Shoppers can zoom in on detail, but only the part of the image they are looking at gets sent to the browser, and only in the appropriate level of detail for how far the shopper has zoomed in.


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