IBM Treats Its Guest to Thin-Client Computing

IBM uses thin clients to provide custom computing services

At IBM's Palisades Executive Conference Center in New York's Hudson River valley, executives from IBM and other companies receive training in business IS solutions, primarily for managing large numbers of users in global networks. Each year, approximately 7000 people (700 people to 800 people each week) spend about 2 1/2 days training at the center.

The training center has two goals: to showcase new technology and to teach people about this technology. Business and technical managers wanted to make the students' stay as comfortable as possible and minimize any computer problems. Thus, the center developed a way to give users access to applications (e.g., email, word processing, and the Internet) and minimize maintenance costs.

IBM created the training center with networking in mind. When IBM built the building in 1989, the company wired the center for a 16 megabits per second (Mbps) Token-Ring network and supplied each of the 206 guest rooms with a PS/2 computer so that guests could work at night. However, this configuration was expensive because of the hardware maintenance it required and the time needed to upgrade applications.

A New Networking Paradigm
In 1996, Art Williams, the research director for the centralized delivery of Windows applications at IBM's Thomas Watson Research Center in Yorktown Heights, New York, ran a pilot program for a network paradigm based on thin-client computing. (For Art Williams' comments on the thin client project at the Palisades Executive Conference Center, see "An Interview with Art Williams," on page 174. For more information about the thin client model, see "Can a Hybrid Network Work for Your Enterprise?" on page 167.) For the pilot program, IBM used an X Windows-based client and a Citrix WinFrame version of Windows NT Server 3.51. The goal of the program was to reduce PC support costs and focus these savings on the server. To do this, IBM needed to change the network paradigm from the traditional PC client LAN and file server to thin-client/server computing, and still provide access to Windows applications.

During fall 1996, IBM executed the 30-seat, thin-client pilot program at the Thomas Watson Research Center, which is known for its high-level projects (e.g., the creation of the Deep Blue computer that beat international chess champion Gary Kasparov). The center also develops and demonstrates practical solutions for everyday computing problems. The thin-client pilot study had three objectives: to establish the feasibility of using the Wintel network with IBM's Network Station Series 300 network computers (NCs), to determine user acceptance of the new network paradigm, and to learn more about the effect thin-client technology has on the total cost of ownership (TCO).

To determine how well applications perform in the new network configuration, IBM used Texas Instruments' Wintach video benchmark application. Specifically, IBM used Wintach to test application performance (i.e., video output) on the new NCs vs. the traditional PC. Text, CAD, and paint programs performed about the same on the NC and the PC, but spreadsheet programs performed better on the NC. Performance differences were based on how the systems transferred data to the output devices. The NCs use X Windows-based technology to download all video, using graphical commands whenever possible. A video adapter then translates the graphical commands into pixel patterns. Paint programs use only a few pixel patterns whereas spreadsheets consist almost exclusively of these patterns. Thus, the spreadsheet programs performed more than twice as well on the NC as they did on the PC.

In general, users responded favorably during the pilot: Users thought the thin-client system responded faster than the PC system and was just as reliable. However, some users complained about the NC's reduced flexibility: User profiles limited access to system configuration tools and the system lacked a 3.5" drive.

The 30-seat, thin-client pilot program was so successful that IBM decided to demonstrate the technology to thousands of users. For this phase, IBM worked with its worldwide service delivery organization, IBM Global Services (IGS), which maintains a client/server development group at the Thomas Watson Research Center. This group first deployed NT Workstation and Windows 95 within IBM, and was selected to spearhead the new thin-client/server deployment project.

Deploying the New System
Brian Smallhorn, manager of the IGS client/server development group, sent his team out to deploy thin clients to approximately 1000 users at five sites in New York and Connecticut during spring 1997. To take maximum advantage of current NT management technology, IGS hired the Taylor Group, a Microsoft Solution Provider with extensive experience in Zero Administration for Windows (ZAW) practices. (For information about ZAW, see Mark Minasi, "Zero Administration for Windows," December 1997.) The experience IBM gained during this large deployment let the company install 240 seats at the Palisades Executive Conference Center in just 1 week at the end of 1997.

The thin-client system at the training center consists of 240 IBM Network Station Series 300 NCs--small black boxes containing 16MB to 64MB of RAM, a video card, and a processor. These NCs run X Windows and connect to a server through Trivial File Transfer Protocol (TFTP). TFTP runs on top of UDP in the TCP/IP suite. Series 300 is a powerful graphics engine that interprets graphics device interface (GDI) commands. You can download only video commands to the clients; thus, video output is quick.

The 240 clients connect to seven IBM PC Server 704 computers running Network Computing Devices' (NCD's) WinCenter 3.0, a modified version of NT 3.51. IBM has set up the servers in a traditional NT LAN configuration. This configuration consists of one Primary Domain Controller (PDC) and one Backup Domain Controller (BDC), each with 512MB of RAM; one file server with 512MB of RAM; one 50GB RAID 5 array (striping with parity); and four compute servers with 1GB of RAM and 8GB of hard disk space. The PDC and BDC process user logons for the domain and supply the TFTP service that lets the clients boot up. The TFTP service also handles all session data transfers. The file server stores user data and user profiles within each user's home directory (the compute servers don't contain user data). The four compute servers provide the necessary applications (Lotus SmartSuite 97, Lotus Notes, Microsoft Office 97, and Netscape Navigator 3.0) to the 240 NCs. Each compute server services 60 users. The compute servers are identical, so if one fails, IBM's support staff can re-create it in 1 hour.

Running more than 200 users in one NT domain might seem unusual. However, the network designers at IBM determined that a network with only a few servers and one domain works because users don't use that much processing power. The 1000-seat deployment demonstrated that even when all users log on simultaneously, CPU utilization is less than 30 percent. However, IBM admits that if all 240 users boot their NCs simultaneously, problems will result. Each NC needs to download roughly 12MB of data to start, which places a considerable drain on the domain controller running the TFTP service and on the network bandwidth on those rare occasions (e.g., after a power outage) when all workstations boot at once. A UPS protects the servers but not the clients; thus, a power outage can cause a traffic problem when power is restored, because the clients have automatically rebooted. However, a bottleneck in the network bandwidth hasn't happened yet because the workstations are rarely turned off. Users don't need to log off because IBM configured the compute servers to log off each NC after 60 minutes of inactivity. When users finish using their computer, they simply turn off the monitor. (When the monitor is off, each NC uses approximately 7 watts of power, or about as much as a nightlight.)

User profiles, which are central to ZAW techniques, play a key role in the training center deployment. Each guest can create custom settings for applications and save all changes to the %SYSTEMROOT%profiles directory on the file server. Although system policies are in place to prevent users from changing the interface (users can access only the Applications dialog box, not the Control Panel), users can change application preferences and have these preferences follow them as the users log on to different computers. For example, if a user bookmarks a URL from within Netscape Navigator, that bookmark will appear in the user's Bookmarks folder when the user logs on at another location. Because the file server stores all user configuration information, you can add or remove compute servers (during maintenance or system failure) and users won't lose their work. (For more information about user profiles, see "A Simpler Approach to User Profiles," page 176.)

Currently, user accounts are location-based (i.e., the center creates a new account when each user checks in). Logons are automatic so guests won't get locked out of the system if they forget their password. However, this precaution means that if a guest uses another computer, that guest's user profile isn't downloaded to the new computer and the user receives the default settings.

The Value of Planning
This speedy installation wouldn't have been possible without some background work. IBM installed the 16Mbps Token-Ring network when the company built the building, so the physical infrastructure was already in place. IBM also spent a lot of time planning how the network would operate and how the thin-client paradigm would affect the network.

Brian Smallhorn sent his team to learn about ZAW strategies and the Registry from Greg Williams of the Taylor Group. Then he created the testing lab, hardware ordering systems, shipping procedures, and onsite deployment teams necessary to deploy the WinFrame software, WinCenter compute servers, and Network Station NCs in a few days.

Results
The training center thin-client network works well on the client and server sides. Guests can work as easily at their training NCs as they can in the office, and the WinCenter 3.0 interface is familiar to users. IBM also provides Lotus Domino's Simple Mail Transfer Protocol (SMTP) email service, so users can send files back to their offices from the training center. Users can have files waiting for them when they arrive at the center if they send the files to the center staff and request to have the data installed in their home directories.

Guests' data is secure: Only the user can access his or her home directory. In addition, center staff delete home directories and accounts when a guest checks out. IBM built the network to give the user interface a consistent look and feel and help minimize distractions as guests move from computer to computer. For example, when a user accesses user-specific Word templates in room 214 and room 148, the templates appear in the user interface to be on the H drive in both locations; however, these templates actually map to different locations on the network.

If a client system breaks down, center staff can disconnect the system from the network and plug in a new system. The client systems are fast. Applications run on the server so users have access to the processing power of four 200MHz Pentium CPUs on each compute server. In addition, the systems use local memory and CPU time only for graphical display. When I tried one guest room client that had 48MB of RAM, PowerPoint and Word 97 loaded almost instantly. Netscape's Navigator, which ordinarily takes more time and processor power than average to load, also loaded quickly and ran a multimedia (sound and video) application at an impressive rate. Even with more than 200 users on one network, bandwidth is sufficient. During the 1996 pilot program, IBM determined that each user required only about 5 kilobits per second (Kbps); thus, the 16Mbps network provides enough bandwidth for all users.

The system works well on the server end and requires little maintenance. Upgrades and fixes are simple. The support staff upgrades applications with disk imaging; that way, they can prepare several disks simultaneously. The servers use hot-swappable disks; thus, setting up a server requires approximately 20 minutes. The training center staff manages user accounts with a scripted interface, so setting up a new user account takes approximately 10 seconds. IBM staff can handle the setup as part of routine check-in procedures. Thus, the plan of Dan Gassert, manager of the Palisades Executive Conference Center, to reduce the time the technical staff spends on client maintenance has been a resounding success. The staff now has more time to dream up innovations. The lives of the Help desk personnel are simpler too. These days, calls to the Help desk focus on application integration rather than problems.

Working Out the Kinks
The installation still has a few imperfections. Users can obtain their profiles only when they log on to the computer in their rooms. In addition, NT limits addressable memory. You can install as much as 2GB of physical memory on each server. However, WinCenter recommends at least 4MB to 8MB of RAM for each concurrent user in addition to the 16MB that the base system requires. This load places a strain on virtual memory addresses. As Greg Williams pointed out, "If 100 users each use 30MB of virtual memory, you start pushing the system to its limit."

Also, applications that store user-specific information in the HKEY_LOCAL_MACHINE Registry key won't work with this thin-client setup (although sometimes you can tweak to map drive letters properly). For example, clients must use Netscape Navigator instead of Communicator 4.x because Communicator doesn't follow Win32 programming guidelines and puts user profile account information (i.e., a list of all the Internet accounts for a profile) into HKEY_LOCAL_MACHINE instead of HKEY_CURRENT_USER. As a result, this information won't follow users from computer to computer because it's specific to one workstation. This situation creates a security risk because user-specific information remains on this computer and is available to other users.

Plans for the Future
Dan Gassert and Rich Russo are excited about the possibilities of the new thin-client network. Now that staff members spend less time on maintenance and more time on innovation, Gassert and Russo are full of project ideas.

They'd like the technical staff to implement smart card technology so that users can log on from any location in the building and download their profiles. Gassert and Russo also want to add Network Stations to some of the training labs: In some cases, users need actual workstations, and letting users install specialized applications locally instead of having IBM staff install them on the application server is more efficient.

IBM also plans to introduce user-driven projects based on feedback from surveys the company gives guests when they check in. Every Monday, staff members review the returned surveys to see what guests want and how the company can improve services. With a 32 percent response rate, they receive plenty of feedback.

Future Needs
In the future, IBM might need to add more Java applications. Although the clients will require more processing power for these applications than they currently need (Java applications execute locally instead of on the server), Art Williams says that the cost of adding power is negligible.

Physical upgrades are a certainty as IBM showcases new technology. Several of the NCs already have flat-panel screens, and IBM plans to install more. New applications to facilitate guest services (e.g., a program that lets guests order food from one of the computers in the game room) are also on the horizon.