Transforming WANs into LANs

You wouldn't accuse any segment of the high-tech sector of orthodoxy. But even by tech industry standards, the market for WAN acceleration is a wild ride. Just ask Silver Peak Systems' founder and CTO, David Hughes, who says that in the WAN space, sometimes "no" means "yes", late is better than early, and you have to add to subtract.

The game plan for Silver Peak came to Hughes while he was working as an executive in residence at Benchmark Capital. He was taking a close look at the branch office and figuring to build an appliance that would improve the link to the home network. But in his talks with potential customers about the problems they were facing, the feedback he was getting was not what he expected.

"I came from Cisco, so I was thinking about it in terms of augmenting their router," Hughes remembers. "And their reaction was, 'We don't want to add any more boxes in the branch. We're actually trying to get rid of boxes in the branch.'

"The first few times I heard that, it sounded like they didn't like my idea," he adds with a laugh.

But then Hughes had a revelation. Maybe his appliance could help facilitate the consolidation or centralisation that customers were trying to achieve. So he started asking these customers exactly which sorts of boxes were giving them problems. What were they trying to get rid of?

Hughes counts them off: "It was Exchange servers, file servers, or they've got this backup system that's not running properly... those were the headaches in the branch, not the router." If only these sites could rip out those servers and deliver mail and files from the central LAN, life would be much simpler... at least for the IT folks. But would the long-distance links be too slow for end-users?

And that's when Hughes began explaining how he could embed a disk array in his appliance that could store all the data the branch needed locally. Thanks to the magic of disk-based data reduction, combined with protocol optimisations that reduced chattiness and latency over the WAN link, customers wouldn't have to sacrifice performance.

Silver Peak's disk-based data reduction eliminates repetitive data transfers by identifying byte-level patterns of data that have travelled the WAN and serving them locally on subsequent requests. For example, if a user opens a remote file that a co-worker previously downloaded, the entire file could be delivered locally. If the file had been changed in the meantime, then only the new information would make the trip. Naturally, the same principle applies to email, Web apps, and other forms of content.

Once Hughes realised that consolidation was the right focus, he had a second realisation: Think big -- in terms of lots of locations, high bandwidth, and heavy traffic flows.

"If you looked at the typical customers of WAN optimisation equipment at that point, they were people with little links that they were having trouble with," he recalls, noting that these were potential buyers of just two appliances. "But this consolidation, that was big institutions that wanted to centralise hundreds of branches, so scale was going to be very, very important."

And so Silver Peak increasingly focused on building larger boxes and accelerating data movement on large pipes. The emphasis on scalability paid off in more ways than one: Once the product hit the market, Hughes and company discovered that the scale features they had implemented were useful in backup and data replication between data centres. Today, storage applications represent between one-half and two-thirds of Silver Peak's business, Hughes estimates.

Looking ahead, Hughes says the company is sticking to its guns and doubling down on its original bet. "If you think about our road map in general terms, it's about doing what we do faster with more data and doing a better job of data reduction -- taking our technology and pushing it harder."

Thus, Silver Peak continues to carve out a successful niche in the WAN arena with a consolidation story years after pioneers such as Expand Networks, Peribit Networks (since acquired by Juniper) and Packeteer began wrangling over Web app acceleration and link optimisation. One of the latest latecomers to the WAN market, Silver Peak seems to have arrived right on time.