One of the fastest paybacks in IT comes from WAN compression. Put compression boxes at both ends of a link and increase throughput without buying more bandwidth. The result is that applications respond faster without signing on for the additional monthly expense of a bigger WAN connection.
Take international specialty-packaging company Pactiv, with U.S. headquarters in Lake Forest, Ill. Last year it installed a manufacturing application called Manufacturing Pro at 12 sites in Europe that are connected by a hub-and-spoke frame relay network. The new application slowed traffic so much that some 128K bit/sec links would need doubling to support fast enough response times, says Matt Haynes, Pactiv’s network manager. That doubling of bandwidth would have doubled or even tripled the price of some circuits, he says.
Before buying that extra bandwidth though, Pactiv tried Expand Networks’ Accelerator compression gear, which shrank traffic enough to eliminate the need to pay for fatter pipes. Based on avoiding that additional cost, the appliances paid for themselves within six and a half months, Haynes says.
Makers of specialty compression equipment such as Expand, Peribit Networks and ITWorx share a basic concept: Their appliances examine network traffic for patterns that repeat and then replace them with shorter patterns. These abbreviations reduce the number of bits that cross the wire, easing congestion. Depending on the type of traffic, compression can reduce it by more than 95%, with vendors promising to cut traffic at least in half.
The boxes sit between WAN routers and WAN links. If they fail, they become passive and traffic passes as if they were part of the wire.
Peribit and Expand have added basic traffic-shaping to their equipment, and traffic-shaping specialist Packeteer has added compression. Experts say Peribit’s and Expand’s traffic shaping doesn’t stand up to Packeteer’s, and Packeteer’s compression lags behind Peribit’s and Expand’s.
Some router vendors also support compression in their gear, but customers report finding shortcomings with that architecture.
McKee Foods, maker of Little Debbie snack cakes, considered purchasing new Cisco gear or upgrading its Nortel gear to accommodate compression among distribution and production sites, but decided against it, says Bo Smith, the company’s IS group manager. The project would have required software and hardware modules as well as new routers in some sites.
“By the time we upgraded the routers for hardware and software, it would have been a wash on the cost, and we would have been tied to one of those vendors,” says Smith, who bought Peribit Sequence Reducer gear instead. The Peribit boxes can be installed at any site regardless of which routers are used and can be moved around to support the most congested links. He says that boosting bandwidth would have cost $5,000 more per month.
Smith never got around to evaluating the performance of the router compression, but as a rule, compression specialists are better at squeezing more out of bandwidth than router makers, says Peter Firstbrook, a senior research analyst with Meta Group. “You don’t expect as much compression out of [a router],” he says.
Firstbrook also says router compression requires a single vendor’s equipment carrying the same version of software at every site. If a business has one problem link with a pair of matched routers at the ends, it might try the router compression at little cost to see if it helps, he says.
Carpe diem
But users might be wary of doing this.
“It’s a router. It’s so critical to your infrastructure that people are reluctant to screw with it once it’s working,” Firstbrook says. Separate appliances compress without affecting router performance, he says.
Some businesses, such as Richardson Electronics in LaFox, Ill., turn to traffic-shaping devices to boost the performance of particular applications across congested connections. Mainframe applications at the company’s hub site were slowing down, so it bought Packeteer equipment to prioritize traffic, says Mark Wolf, director of IS operations for Richardson. It worked for a while, but with a jump in e-mail traffic with large attachments he needed to try something else.
He started to move Microsoft Exchange servers to branch offices to cut down on e-mail traffic, but before he completed that project he tried Expand compression boxes. They gave him 900K bit/sec throughput on a 56K bit/sec link, he says. “I turned off my Packeteers,” and kept the Exchange server located centrally, Wolf says.
Richardson has installed 52 Expand boxes and had a payback in as little as three months for a 128K bit/sec circuit to China. Links still fill up, and he has to order more bandwidth, but it is in 64K bit/sec channels rather than doubling the bandwidth on a connection, he says.
Compression equality?
Wolf says not all applications compress equally well. ZIP files already are compressed, so they don’t get much smaller. The vendors constantly are updating their algorithms to address specific applications.
“Software developers spend time on the functionality of their application, not on making it network-efficient,” Firstbrook says. “[Compression vendors] can look at a big app and make it more efficient. There are lots of little things you can do that turn into a big difference.”
Vendors also are constantly fine-tuning other features of their gear to get more out of them. For instance, Expand started fragmenting large packets earlier this year so short, time-sensitive voice-over-IP packets wouldn’t get stuck behind large packets. And earlier this month, Peribit added features to make IP Security VPN traffic perform better and to give it higher priority.
According to Firstbrook, compression gear requires little management or maintenance once it’s running. Users are more likely to monitor the devices to pull down traffic statistics they gather as a resource for other projects. He sets the monthly management cost at $175 per box, but says that is probably high.
Initial setup of the equipment can be challenging as well. Wolf says his company has installed 52 of the Expand boxes in the past two years and recently installed one on a Sprint frame relay link in Canada. “They say they’re not seeing any difference in performance,” he says, but expects that after some troubleshooting the device will perform as well as the rest.
The market is young. Peribit shipped its first products less than two years ago. Firstbrook predicts that in three or four years, with demand increasing for these devices and with Moore’s Law driving down hardware costs and improving performance, this sophisticated compression will become a feature on routers without jeopardizing router performance. But customer demand also will have to grow to make it worthwhile for the router vendors. With sales of less than $33 million in 2002, according to NetsEdge Research Group, the market for these appliances is still very small.
In the meantime, Firstbrook says, it’s pretty safe to give the equipment a try.
“If the payback is less than a year and if they go out of business in two years, I don’t care. The box has already paid for itself,” he says.
