Silver Peak Systems says it has a better way to transfer data over wide area links. The premise is that it doesn't transfer the data as often as it's requested or in its complete form.

It's not a new concept to reduce the amount of packets, bytes, files and traffic that traverse corporate WANs to optimize performance , but start-up Silver Peak believes it is achieving the end goal of reduced congestion and latency on the WAN in a unique way. The Mountain View, Calif., company, which raised some $12.5 million in venture funding, this week will begin shipping its flagship product suite.

Silver Peak's Network Memory employs technology that the company dubs local instance networking, in which the appliance watches traffic and recognizes patterns. The product comprises appliances loaded with software and installed at either end of a WAN link - for example, in a data center and at branch offices. When the data center appliance sees a pattern of bytes that it remembers already sending over the WAN, it will only send a reference to the branch office box, letting it know the box already has all or parts of the content and telling it to forward the content on to the requesting end user.

The data center appliance can be used to optimize traffic at either Layer 2 or Layer 3, sitting behind the router or peering with it , and the branch appliance sits behind the router. The appliances are unaware if the packets they are passing along contain e-mail or a PowerPoint presentation; they just identify that a particular sequence of data has been repeated and does not need to be sent over WAN links again. Company officials say that, unlike some application acceleration tools, Network Memory can optimize any type of traffic, including TCP, UDP and more.

"We are not simply a TCP proxy or TCP-only; we can optimize proprietary applications, streaming traffic and UDP," says Craig Stouffer, vice president of worldwide marketing. The appliances are also loaded with storage, up to 2 terabytes in the data center and less for local appliances, to provide customers with adequate memory for weeks and potentially years depending on the content, the company says.

With its dual-box architecture, Silver Peak will compete with the likes of Peribit (which has been acquired by Juniper) and Riverbed, but company officials say the product would be complementary to tools from the likes of NetScaler (recently acquired by Citrix ), F5 Networks and Redline Networks (also acquired by Juniper), which can help customers reduce the number of servers needed in a data center to speed Web application traffic over the WAN.

Ann Bednarz is associate news editor at Network World.