A question of bandwidth

How to balance your company’s speed needs and budget

Several readers have asked, “How much bandwidth do I really need?” for a small business Internet connection. Others ask for guidelines on how much bandwidth to recommend to their customers. My quick answer is always “More,” but let’s look at some guidelines for determining bandwidth needs and balancing between bandwidth (more is good) and expense (less is good).

There are two key indicators for bandwidth you can control and one you can’t. You know how many active Internet users you have, and whether you host any e-mail or Web servers. What you can’t control are the bandwidth speed options your ISP can offer based on your distance from the telephone company’s central office (for DSL) or network topology and designed load (for cable).

First, differentiate between number of computers in the company (whether two for a home office to up to 50 for a successful small business) and the number actively using the Internet. My rule of thumb for determining minimum acceptable performance is to triple dial-up speed for each active Internet user (about 150K bit/sec). That way, performance will be much better when only a percentage of regular users are downloading from the Web at once.

Most users download much more traffic than they upload. When you browse, your computer sends out small blasts of information, such as a URL like www.nwfusion.com, with a few instructions. A thousand times that much data is returned in the form of Web pages full of images, and possibly audio and video.

Handy it works that way, because ISPs provide two different data pipes to your business. The large data pipe comes in, but only a small pipe goes out because ISPs strongly favor pushing information out to you and don’t expect much in return. Hence the A for “asynchronous” in ADSL, although phone companies generally just call it DSL.

At the low end, my provider SBC offers a 384K bit/sec-128K bit/sec DSL product for businesses for $39.95 per month. At the high end, it offers a 1.5M bit/sec/6M bit/sec-384K bit/sec for $159.95 per month. Using my rule of thumb, two users would find the low-end acceptable, but 1.5M bit/sec can support only 10 concurrent surfers comfortably. The full 6M bit/sec downstream speed would keep about 40 concurrent users happy.

The indicator you can’t control is your distance from the DSL provider’s central office, which affects the fastest allowable speed. My home office is more than 30,000 feet away from the phone company’s central office, so the fastest DSL I could get was 144K bit/sec. (Actually, it was iDSL using ISDN technology.) It’s O.K. for one user, but that’s all. Before committing, check with your provider because new technologies stretching DSL distance limits and neighborhood repeaters can bump your allowable speeds back up to a usable range. Or you can switch to cable broadband, as I did.

If you host your own e-mail or Web servers, ADSL won’t work well. After all, if you have a 768K bit/sec downstream connection and you’re trying to download a file from a server with a 128K bit/sec upstream line, that hourglass gets old.

I recommend small companies not host their own Web servers for two reasons: bandwidth costs and security. SBC’s price for a 1.5M bit/sec synchronous DSL line nearly doubles the cost of the ADSL line, from $160 to $290 per month. For a fraction of that, you can rent outstanding Web hosting service from any national provider, and let it worry about downloading all the security patches and monitoring all the hacker alerts each week.

My only exception to this recommendation applies to companies with enormous internal e-mail traffic. If this sounds like yours, set up an internal e-mail server on the house network and fetch outside e-mail from your hosting service every 5 minutes. Again, this is cheaper and less trouble than paying for the upstream bandwidth.

Competition may be limited in broadband services today, but it still exists. Even if you’re happy with your current ISP, routinely get quotes from competing vendors. If someone offers a great deal, give your current supplier a chance to match the services and/or prices.

If your current ISP matches the new offer to keep your business, you win. If it doesn’t, you already have a friend waiting at your next ISP.