Enterprise Rent-A-Car is venturing where few, if any, companies have gone before. The St. Louis-based firm plans to deliver Microsoft Office and internally developed car-rental applications to 5,000 branch locations equipped with Windows CE-based terminals. Those thin-client devices will access the applications through the enhanced Terminal Services features in Microsoft's upcoming release of Windows .Net Server 2003.
For more than 10 years, branch employees have rented out cars using 5250 terminals that link back to the company's AS/400 servers in St. Louis. But Enterprise wants to replace the limited-function green screens with a more graphical interface and give its users a more PC-like environment that will support new features and capabilities, says Mark Adams, an assistant vice president of information systems at the company.
Adams says that Enterprise also wants to retain its existing support model for its 5250 terminals because it knows well the effort required to support full-blown PCs. Enterprise settled on Windows CE-based thin clients because it found them easier to manage and configure and considered them more consistent across vendor lines than Unix- and Linux-based devices, says Derik Reiser, director of platform solutions at the company.
The Windows CE terminals launch Microsoft Remote Desktop Protocol (RDP) 5.1 client software and establish sessions either through a LAN to a server in the branch office or through a shared frame-relay circuit to servers at Enterprise's headquarters.
As part of Microsoft's Joint Development Program, Enterprise has been testing Terminal Services at 18 branches that have two-processor servers running locally and at two branches that connect to four-way boxes in St. Louis.
But the ultimate scope of the project is far more ambitious. During the next 24 months, Enterprise plans to roll out Windows .Net Server 2003 to 2,500 of its larger branches and connect the remaining 2,500 to central servers in St. Louis.
The sheer scale will set the Enterprise project apart from the typical Microsoft Terminal Services deployment, according to Mark Margevicius, an analyst at Gartner. He says that 250 to 300 clients has been the "magic number" for Terminal Services. Beyond that, most companies have gone to a more scalable product, such as MetaFrame XP from Citrix Systems.
David Friedlander, an analyst at Giga Information Group, says that even though the Windows .Net version of Terminal Server is improved, he still doesn't expect many companies the size of Enterprise to deploy only the Microsoft product. He says others will likely turn to MetaFrame because of its support for a wider range of clients, advanced manageability and security features for remote access.
Enterprise considered MetaFrame as well as several open-source options, but for the lighter needs of its branches, it found the Microsoft Terminal Services approach sufficient, Adams says.
"We believed that running fewer products would make the solution less complicated to support over the long haul," he says. "With the Windows .NetTerminal Services combination, we had fewer pieces and parts to manage."
Plus, .Net Server offers enhancements that Enterprise has found useful. For instance, the new group policy management console lets the company apply policies to a collection of servers. When Enterprise adds a server to the group, the server will inherit the same configuration settings as each of the others in the group, Reiser says.
Policies also can be applied to each user's account at log-on to indicate which data, directories and drives the user can access, he says.
Reiser says he also likes the new session-directory feature, which tracks user connections to specific servers. If a user is disconnected, he is pointed back to the server where the session originated. In the past, he might have reconnected to a different server, possibly losing work, Reiser says.
The MetaFrame Alternative
Citrix's MetaFrame has many capabilities that aren't found in Windows .Net Server, such as built-in load balancing, which directs users to the least busy server.
And Enterprise is familiar with the benefits that third-party products can add to a Windows Terminal Services deployment, because it has delivered enterprise resource planning applications to administrative offices using MetaFrame, Adams notes. But he says Enterprise won't need Citrix's advanced management console, since it won't be running a complex set of applications on its server farm. "Most of our applications will be delivered with browser-type technology," he says.
Support for heterogeneous clients isn't necessary because Enterprise plans to use only Windows clients. And because the clients will connect via a private network, the Terminal Server product won't be relied upon to provide security, Reiser says.
MetaFrame also helps companies that need to do complex application publishing, Reiser says. But since Enterprise is publishing an entire desktop to its Windows CE devices, which run only the Windows CE operating system and the RDP 5.1 client, those features aren't critical.
"In an all-Microsoft environment, with Microsoft clients and servers and no intention of supporting anything else, the Microsoft [Terminal Services] approach is certainly a reasonable one to take," says Dan Kusnetzky, an analyst at Framingham, Mass.-based IDC.
But even in an all-Microsoft environment, there's a need for considerable advance planning. Enterprise, for instance, had to roll out Active Directory in conjunction with the Terminal Services project.
"Don't underestimate the amount of time and effort you need to put into how this component intertwines with the other portions of your architecture," Adams says.