Kemp Simplifies Load Balancing for Windows Terminal Services

Small and midsize businesses looking for a simpler way to load balance Microsoft Windows Terminal Servers may get their wish on Feb. 6 when Kemp Technologies introduces a new upgrade to its appliances.

The commodity load balancing provider added new Layer 7 content switching support for Microsoft’s Remote Desktop Protocol, in addition to its existing HTTP support. It also took steps to make it much simpler for SMBs to configure load balancing for Windows Terminal Services.

“Microsoft’s Session Directory Services are extraordinarily difficult to set up. We’ve made it possible to do in a couple of screens. If the user selects load balancing, all the functional elements are already preselected,” said Peter Melerud, director of business development at the Medford, N.Y., company.

With the upgrade, Kemp’s LoadMaster appliances can prepopulate common configuration settings related to WTS, including persistence, health checking and resource-based load balancing.

Kemp, which also provides Secure Sockets Layer acceleration in its appliances, added hardware and application-level health checking for WTS.

The software upgrade for Kemp’s LoadMaster appliances works with the Microsoft Session Directory Services in the new WTS 2008 terminal server. That support enables session persistence so that if a session is dropped, it can be resumed with the same terminal server.

“The terminal server queries the [Microsoft] session broker to see if [a request] was from a prior session that was established.  If it was, it passes a routing token to the client; the load balancer reads that token and sees which server the session needs to go to,” said Melerud.

If customers don’t want to install the dedicated server required by Microsoft’s Session Directory, they can opt to use Kemp’s own Layer 7 persistence model implemented in its LoadMaster appliances. 

“We found that to be extremely valuable, especially where the environment can’t afford that extra hardware,” said Melerud.  

Kemp is unique among commodity server load balancing vendors in its support of terminal services, according to Steve Steinke, research director for networks at The 451 Group in San Francisco.

However, the lion’s share of the terminal services belongs to Citrix with its Presentation Server, which incorporates its own load sharing technology, Steinke said. The upgrade is available Feb. 11.