Sound Transit in Seattle unclogged slow WAN links that hindered railway-improvement projects by using WAN-optimization gear that made traffic run faster and cost much less over time than other options.
Now applications on the network perform well, reducing transaction time for a test set of traffic by as much as 69 per cent. And, as an unexpected bonus, the transit authority has also dramatically cut back bandwidth that was unnecessarily dedicated to VoIP thanks to data gleaned from the Silver Peak WAN-optimization gear it uses, says Garv Nayyar, senior integration engineer for the transit authority.
The Sound Transit WAN is arranged in a hub-and-spoke configuration, with a headquarters data centre that feeds seven other sites via point-to-point T-1 connections.
Workers at the remote sites access a variety of applications, including Microsoft SharePoint for file sharing, Opentext Livelink EMC for document management, Primavera Expedition for project management, and Microsoft Exchange for e-mail.
Part of the project calls for workers to send construction photos and CAD drawings over the WAN, transfers that slowed down everything else on the links, Nayyar says. “The problem was if somebody was pulling a 5MB file it just took the site down or it would slow them down for a few seconds, making it so other folks couldn’t work effectively,” he says.
End users complained about the delays and demanded that something be done. “They wanted us to put either servers at all the local sites or add another T-1 line or possibly up to three T-1 lines to each site,” he says.
In addition to those possibilities, he looked into WAN-acceleration gear from Cisco , Riverbed and Silver Peak. Cisco kept pushing back the deadline for when its gear would be ready to test and Sound Transit couldn’t wait, Nayyar says. He could not get