Computer-aided design (CAD) application file transfers are notorious bandwidth hogs over the wide area network (WAN) even under the best circumstances. Add mobile users to the equation and the WAN manager's head
"Right now, it would be crippling if my mobile [WAN optimization] controller were to fail," said Michael Vassallo, senior network administrator at Dancker, Sellew and Douglas (DS&D), which is headquartered in Somerville, N.J. "I would have to see which users I could get to come into the office and ... start limiting on a case-by-case basis what users actually connect to the VPN to allow enough bandwidth for everybody."
When Vassallo deployed Riverbed Technology's standard Steelhead appliances throughout his branch offices about two years ago, he originally sought to reduce the number of WAN connections at each branch and improve data backup over WAN links. The addition of new offices and users after a series of acquisitions had taken its toll on the WAN, he said.
While evaluating multiple WAN optimization vendors, including Silver Peak Systems and Packeteer, Vassallo discovered that only Riverbed at the time offered a mobile product. Vassallo expected users to be moving between branch offices more frequently and taking advantage of the company's work from home policy, so he also deployed the Steelhead Mobile Controller in his data center and installed the mobile WAN optimization clients on the devices of 60 users.
The impact and performance gains of mobile WAN optimization have been dramatic, he said.
A designer and AutoCAD user who works from home full-time recently requested 465 megabytes of data one afternoon, but thanks to the caching and deduplication capabilities of the mobile WAN optimization controller and software, only 38 megabytes traversed the WAN to her laptop, Vassallo said. That same day, another designer requested 177 megabytes, but Riverbed was able to reduce the request to 29 megabytes.
"Instead of having two users pulling almost a gig of data, under 100 megs went out across the wire," Vassallo said. "Now, more bandwidth is available to [my] other users, so [I] can get more users on [my] VPN appliance because there's less data having to be transmitted and less congestion. Less congestion makes for a better user experience, and when users are happy, I'm happy."
Blizzard strikes, mobile WAN optimization keeps business running
When the Northeast was hammered with snowstorm after snowstorm this past winter, many of DS&D's employees chose to work from home, Vassallo said. In some cases, offices were completely shut down. But mobile WAN optimization meant business didn't stop.
During one of the worst snowstorms to hit the region, about 25 designers and salespeople connected to the WAN from home using the VPN and mobile WAN optimization. Another 60 users in administrative and executive roles connected from their home computers by using a free, Web-based remote desktop access tool, LogMeIn.
"If [I] didn't have the mobile [WAN optimization] controller optimizing the IPsec users through the VPN and compressing all their data down, nobody would've gotten any work done.
Senior Network Administrator, Dancker, Sellew and Douglas
"If people didn't have to be here—even if the office wasn't closed—they weren't here," Vassallo said. "If [I] didn't have the mobile [WAN optimization] controller optimizing the IPsec users through the VPN and compressing all their data down, nobody would've gotten any work done because the link would've been just clogged with [requests] to pull data for the VPN users."
Mobile WAN optimization benefits branches, too
Although Vassallo is only using the 30 licenses that came with the Steelhead Mobile Controller, he can support more than 30 clients at any time.
The latest version of Riverbed's Steelhead Mobile software, 3.0, enables WAN managers to offload some mobile client users onto what's called "branch mode." When a Steelhead Mobile user is physically at a branch office that has a Steelhead branch appliance deployed, the mobile controller recognizes the IP subnet and directs the mobile WAN optimization client to "talk to" the branch appliance while the user is there, Vassallo said. That session does not use up one of the mobile WAN optimization software licenses.
Additionally, standard branch office users benefit from having a mobile user swing by the office thanks to "branch warming," Vassallo said. After data passes through a WAN optimization appliance for the first time, it remains cached there. Subsequent requests only go as far as the branch appliance or mobile client, as opposed to all the way to the server where the data is hosted.
Vassallo's branches only have desktop PCs, so a mobile user working out of a particular branch that day, such as a salesperson, must connect via the VPN on a laptop. If that salesperson has "warmed" the branch appliance with a cached presentation or spreadsheet, another user who works only at the branch PC and needs that document a day later obtains it much faster, Vassallo said. Likewise, anything requested while at a branch office is cached on the mobile WAN optimization client.
"[This helps us by] improving optimization for all systems—not just the mobile user," he said.
Let us know what you think about the story; email: Jessica Scarpati, News Writer.