Riverbed helps speed WAN traffic

Riverbed Technology is launching its first product, an appliance that squeezes more traffic onto WAN links and also reduces the potentially crippling delay that certain chatty protocols can cause when sent across congested wide-area connections.

With the company's Steelhead appliances, customers can speed up specific applications so end users don't get frustrated with performance and swamp help desks with calls. Performance for some protocols can be as much as 100 times better using Steelhead boxes, Riverbed says.

The products compete with gear made by Expand, ITWorx, Packeteer and Peribit, but use unique variations on how to make narrow pipes work faster, says Peter Firstbrook, senior research analyst for Meta Group.

Devices made by all these companies sit at either end of WAN connections and use different types of caching and compression to reduce the amount of traffic that has to cross the links, he says. But these methods don't make chatty protocols any less chatty; they still conduct thousands of interactions, each of which takes more time over the WAN than it would on a relatively faster LAN, Riverbed says.

By spoofing some of these interactions on the local Steelhead box, they can be made more efficiently and thereby reduce the time to make a remote transaction with a server. For instance, if a remote user tries to open a Microsoft Word file on a remote server, the Steelhead appliances recognize the initial steps of the transaction and generate appropriate responses to the server and the client. When the transaction is complete, the Steelhead devices compress the sought file and send it. Riverbed calls this process "transaction prediction."

Merrill Lynch is looking to use Riverbed boxes to support its move to centralize servers rather than to support individual print and application servers in many branch offices, says Dave Cohen, a vice president at Merrill Lynch. Moving servers to central sites reduces the amount of maintenance and support that branch offices need and frees up servers for other purposes, he says.

"It's compelling to centralize all that equipment," he says.

Many of the applications use Microsoft's Common Internet File System (CIFS), a chatty method that would mean unacceptable delay over the WAN.

"This is an end-user experience hurdle you have to get over. If they notice too large a time lag to store a file, they will be unwilling to use the solution," Cohen says.

Merrill Lynch's lab tests of Steelhead devices showed they meet Riverbed's claims to reduce delay by 100 times, Cohen says, which means delay will be acceptable.

Initially, the Riverbed appliances will perform transaction prediction with CIFS and messaging API traffic only, but eventually will expand to other traffic types, the company says.

Steelhead devices also store traffic on hard disks so their software can perform historic searches for patterns of data that cross the network repetitively. When these patterns are discovered, the Steelhead can represent these patterns using fewer bytes and send the representation across the WAN connection. It is deciphered at the other end by the Steelhead device with which it is paired.