Riverbed Technology claims to be able to speed up WAN traffic between data centres and individual computers without the need for a dedicated WAN acceleration appliance at both ends of the connection.

Through a variety of optimisation functions, Riverbed Steelhead Mobile software can reduce the amount of traffic that has to cross the WAN, make TCP work more efficiently, and streamline individual applications.
Previously Riverbed required an appliance at both ends of WAN links to speed up traffic. Other vendors including Blue Coat, Citrix, FastSoft and Ipanema all have claims to one-ended WAN acceleration as well, and Juniper says the capability is on its roadmap.

Some Riverbed users say Riverbed WAN optimization between Steelhead devices reduce traffic by 80 percent, and the company claims results with Steelhead Mobile are similar.

Padmini Dhulipala, vice president of IT for valuation company AccuVal Associates, said beta versions of Steelhead Mobile reduced WAN traffic 60 percent to 90 percent, and cut transaction times to 20 percent. The company already had Steelhead appliances connecting a site in New York and one in Rhode Island with its Wisconson headquarters, she said

"Most of our users are mobile users that travel and work from hotels or from home," Dhulipala says. "Before they just put up with [slow speeds] or put [needed data] on their laptop."

The new Riverbed software works in conjunction with its Steelhead WAN optimisation appliances, which are generally located at large corporate sites and data centers. The client and appliance synch up to determine what traffic to accelerate and what techniques to use to do so.

While the mobile software interoperates with the appliance as is, it also requires a separate mobile appliance in order to work. The Mobile Controller issues a license to remote computers as they try to connect to Steelhead appliances. Riverbed sells packages of licenses that are distributed as needed. So as a computer ends its session with a Steelhead appliance, its license is returned to the pool and can be assigned to a different computer.

Controllers also issue policies to the remote computer and compile reports on how well traffic is optimised, port by port and protocol by protocol. Initially the mobile software supports Windows 2000 and XP and will support Vista in September.

The software is also compatible with VPN software from Cisco, Nortel, Juniper, OpenVPN, Microsoft, Check Point, Citrix and Aventail so traffic is optimised before it is encrypted for the VPN tunnel. After it is in the tunnel, encryption would make it impossible to optimise.