Lab test: Riverbed Steelhead and Steelhead Mobile push the WAN performance envelope

I sometimes wonder why there aren't any movies made about IT superheroes. Sure, there's always Superman (able to leap tall buildings in a single bound) and Batman (the caped crusader), but what about WANman – the IT superhero that accelerates high-latency traffic and saves the company from additional Internet bandwidth costs? Well, the tights and cape might not go over well (except on casual Fridays), but any IT staffer that can give enterprise users more performance is well on their way to superhero stardom.

[ Riverbed Steelhead 4.1 and Steelhead Mobile 1.0 were selected for an InfoWorld Technology of the Year award. See the slideshow of all winners in the networking category. ]

Luckily, WANman has his own utility belt when it comes to making traffic flow faster over the WAN. A variety of hardware solutions available attack the problem using compression, TCP/IP optimization, and advanced caching techniques, all in an effort to get more out of what is available. Riverbed Technologies has long been out in front of the WAN optimization and acceleration space, helping IT staffers become superheroes in their own right. Riverbed not only addresses site-to-site WAN optimization, but now has a software client for mobile and small branch office deployments. Both appliance and client are based on the same optimization engine, and in my tests proved very adept at making WAN circuits appear cleaner and faster than they really were. 

Steelhead Mobile 1.0.2

Not every situation needs – or can justify – a hardware-based solution. In many cases, what is needed is a software client that can provide the same type of WAN acceleration as a full-blown appliance. The Steelhead Mobile client is one of the first WAN acceleration clients for individual users. Steelhead Mobile provides all of the basic features found in the Steelhead appliance: sequenced byte reduction (SDR), TCP optimization, and CIFS- and MAPI-specific support. A central management appliance, the Steelhead Mobile Controller, manages the optimization and cache policy for each deployed end point, and collects performance metrics for reporting. The only thing missing from this release is HTTPS support.

Testing Steelhead Mobile required a slightly different test bed than what I've used in the past for site-to-site optimization. This go-round I used my trusty Shunra VE to emulate two different WAN circuits and physical connection types. One scenario mimicked a typical cable modem connection (3Mbps/512Kbps, 65ms latency) to a Dell OptiPlex client PC running Windows XP Pro. The other depicted a Wi-Fi hotspot with the Shunra emulating a DSL connection (1.5Mbps/386Kbps, 50ms) over a true 802.11g wireless link back to the same Dell PC. As in my previous tests of WAN devices, I used the Macro Scheduler utility from MJT Net to execute and time the tests.

The performance increases delivered by the Steelhead Mobile client were nothing short of tremendous. One of my tests, copying a large number of small files over CIFS, took longer than 20 minutes to complete over both WAN circuits without optimization. On the first pass with Steelhead Mobile installed, the transfer took just over 5 minutes to complete – a 3.9X increase in performance. Other tests over CIFS showed similar results, with FTP traffic posting a 1.5X improvement on first pass. Saving a file attachment from an Exchange server showed the most modest increase, a 1.7X improvement on a cold pass.