by Alan Joch
Traffic shaping can start networks humming when it comes to network performance, conventional wisdom isn’t always so wise. For instance, ask a network-service provider or server vendor how to beef up a tired network, and you’ll probably hear a simple solution: Throw more bandwidth and processing power at it. There are times when this is the only answer to poky servers, but now small companies have another, potentially more effective choice for turbo charging their networks.
The solution is called traffic shaping, and it’s coming down from large corporate networks like online brokerages and auction sites that live or die on staying up and staying fast. Traffic shaping is a refinement of traditional network monitoring that identifies data bottlenecks and shows you where to hook up a new server or an extra router.
A new generation of traffic shaping hardware and software, priced for performance-craving small companies of 100 people or less, now lets managers unplug traffic jams and give high-priority data the bandwidth it needs to flow without a hitch. Like the laws drivers follow when they let an ambulance go by, traffic shaping provides rules of the network road for businesses in the Internet age.
“Traffic shaping lets you use current resources more effectively, especially as small companies move to e-business and consistent response times become essential,” says consultant John McConnell, president of McConnell Associates in Boulder, Colo.
At their best, traffic-shaping products can help a network manager squeeze more transactions per second out of the communications system, while simultaneously lowering the amount of time it takes applications stored on central servers to respond to user requests. Traffic shaping hardware and software enforce the rules you create for what types of data get high priority in terms of the bandwidth amount or a right-of-way through the network pipes. Low priority data waits while essential information flows past.
PROCEED WITH CAUTION
While traffic-shaping products can get businesses off the bigger-server/greater-bandwidth treadmill, they’re expensive enough to require careful planning and studious product selection. First, decide if traffic shaping really is the answer to your performance problems. If the network is just too small to handle the amount of data being sent through it, traffic shaping won’t work at all, says Bruce Robertson, vice president of the consulting firm META Group Inc. in Reston, Va. Similarly, make sure the most important data is stored where it can be accessed the quickest.
“If data is in the wrong place — in Tokyo, and your headquarters is in Boston — traffic shaping won’t help,” says McConnell. You may need a computer consultant or VAR to help take stock of your overall network and find ways to make the existing structure more efficient.
Next, decide if performance is a live-or-die characteristic of your business. If you use the network to carry e-mail and some files from desktop to desktop, minor traffic delays won’t hurt profits. However, if you’re an e-business that takes credit-card orders over the Web, delays can produce frustrated customers and lost sales. “Eight seconds is the limit. If a customer has to wait on your Web site longer than that [to process an order], they’ll probably go away,” says McConnell.
If decide traffic shaping is the way to go, be ready to budget anywhere from $5,000 to $30,000 for the hardware and software, depending on the size of network and whether runs simple Ethernet or pricey ATM communications. Also, unless you’re a technophile, enlist the help of a VAR or computer consultant to help choose and install traffic-shaping products. Expect to pay $75-$125 an hour for their services. The good news, according to experts, is that once the equipment’s in place, the graphical interfaces on most products are easy to use even if you’re not a networking guru, so training costs are nil.
Traffic-shaping products come in two varieties. The first, called “queuing,” controls the data flow by simply slowing nonessential communications (or stopping them momentarily) in favor of more important data. The second approach, known as “rate shaping,” works for networks using TCP/IP communications protocols. This technique basically guides the hardware that’s sending data to either slow down or speed up transmissions based on the performance of the overall network and the type of data being sent. Because rate shaping is a TCP/IP-specific technology, it doesn’t work if you’re downloading a song from the Web or video-conferencing with an important client. For businesses that need it, there are products from rate-shaping vendors like Packeteer that automatically switch to queuing for non-TCP/IP traffic.
MAP IT OUT
It takes more than simply purchasing traffic shaping hardware and software to get the company network running smoothly. The best products on the market won’t work if the network administrator has not developed efficient transmission policies. Depending on the business, high priority data could be orders coming in over the Web, communications from top clients, any audio or video transmissions that would become incomprehensible if packets were delayed, or communications from a core business application, such as a workflow program.
Take a look at the data flowing through your network, and rank each kind on a sliding scale from most important to least. Then decide how to treat each data type. You can specify that audio and video traffic always get multiple-megabytes of bandwidth to assure smooth reproduction, while people browsing the Web get a single megabyte from the pipeline. You might decide to limit the size of e-mail attachments coming in or out or to automatically route graphics files through specially designated channels.
When it’s time to evaluate products, Robertson suggests companies start with the vendor that sold them their routers. Traditionally, routers have performed less effectively and have been harder to use than products dedicated to traffic shaping, but improvements are in the pipeline. Look for companies like Cisco and Lucent to catch up in this year’s product introductions.
TAKE A TEST DRIVE
To ensure that you get the right product, compare router offerings to traffic shaping products that use queuing to prioritize the data flow. Also, ask the vendors to supply loaner evaluation equipment so you can see which product works best on your particular network.
Once you’ve developed a short list of traffic-shaping candidates, evaluate how easy the graphical interface is for monitoring traffic and adjusting priorities. Since all critical data flows through the traffic-shaping equipment, a breakdown could bring your business to its knees. Make sure you’re comfortable with the product’s fault tolerance capabilities. Some products simply shut down the traffic-shaping capabilities, letting the network run as if the equipment weren’t there. Other products require redundant systems that click on when the main traffic-shaping device hiccups. Finally, test how well each product can distinguish among different types of traffic. The more detailed a product can be about differentiating data, the more control there is in setting priorities.
With the right products installed on a well-constructed network, bottlenecks can be a problem of the past. Traffic shaping won’t help every lagging network, but it can be the right choice for companies that need to keep business-critical data in the fast lane.
