Clogged pipes on wide-area networks are prompting some companies to turn to packet shaping to clear a path for priority traffic instead of adding bigger network pipes.
For example, Roto-Rooter Services Co. is installing a hardware device called WiseWan at its new call centre in Fort Lauderdale, Fla., according to Robb Thomas, communications manager at the Cincinnati-based sewer and drain pipe services franchiser.
WiseWan, from NetReality Inc. in Santa Clara, Calif., lets network managers reserve portions of available bandwidth on any given WAN connection by type of application, effectively giving packets from one application higher priority on the network than packets from another.
Thomas said he already has two WiseWan units in place, one on a 1.5Mbps frame-relay hub in Cincinnati that connects to sites nationwide and one on a 768Kbps circuit at a Chicago call centre that manages operations for eight remote locations.
He uses the WiseWans to set aside a portion of smaller private virtual circuit (PVC) bandwidth some running at 64Kbps and costing US$250 to US$300 per month per circuit hosted by the Cincinnati and Chicago locations for Roto-Rooter’s proprietary customer resource management application. The remainder is split between Lotus Notes and Web browser applications.
Thomas said packet shaping has reduced customer wait time and has held down service provider costs by squeezing more performance out of existing frame-relay circuits.
Thomas said moving up to bigger pipes wouldn’t necessarily resolve application response issues because there’s still no guarantee that an adequate amount of bandwidth on any given pipe would be specifically available for mission-critical applications. “Going from 64Kbps to 128Kbps on our smaller PVCs could easily double our service provider costs,” he added.
Mike Misterek, a network manager at PepsiAmericas Inc. in Rolling Meadows, Ill., is using packet shaping to make sure mission-critical network traffic isn’t delayed by Web browsing and e-mail traffic.
Misterek said his company uses Packet Shaper from Packeteer Inc. in Cupertino, Calif. Although both Packet Shaper and WiseWan prioritize traffic by application, they work in different ways, said Tere Bracco, an analyst at Current Analysis Inc. in Sterling, Va.
Packet Shaper, Bracco said, sits between the LAN and the router going out to the WAN. NetReality’s WiseWan, in contrast, sits between the router and the WAN, said Bracco.
“WiseWan works with your service provider to ensure priority for an application when packets leave the site,” Bracco said. “[But] if you have a virtual private network where the packets are encrypted before they get to the router, the WiseWan can’t recognize the application and can’t assign a priority to it. Packeteer, on the other hand, because it’s on the LAN side of the router, will identify applications and assign priorities to packets that go with those applications before they hit the router.”
Yet the Packeteer product doesn’t have the ability to look at traffic conditions across the WAN to the same degree WiseWan does, Bracco said. What’s needed but not available are devices that can do packet analysis on both the LAN and WAN sides of the router, she said.
