Thin client computing has been given a bad rap because the initial costs of purchase may be high. But, this is about to change as the technology matures and bandwidth connectivity and reliability escalates.
Thin client computing, also known as "server-centric computing" or "virtual user interface software", differs from the traditional client-server paradigm in that its architecture basically centralizes control of an enterprise environment's software in order to deliver its attendant benefits.
The newest systems make client software a standard browser plug-in, extending the hardware that is supported. On the back end, administrators can configure the systems to let users access applications though an intranet Web page. Proprietary protocols enable thin client products to offer faster access to back-office applications on low-bandwidth wide area networks while reducing infrastructure and administration costs.
Compared with desktop PC systems, thin clients offer several promises. The best known of these is perhaps the reduction of equipment maintenance and upgrade costs because of the need to accommodate more resource-intensive applications. Martin Gilliland of Gartner estimates that thin clients have more than a four to five year life cycle when compared with a conventional PC's three to four year life cycle.
With software upgrades only needing to be done on the server, the process is also easier, cheaper and faster to execute; almost no software resides on the thin client. Fiona Hee, marketing manager, Asean Citrix Systems explained that with thin clients having no hard drives and drawing their functionality from servers, power consumption was reduced. She estimated that power consumption of a thin client at 14 percent of a PC's.
Moreover, since nearly every file or piece of software resides on servers in a thin client environment, security and disaster recovery capabilities can be significantly increased.
"It is harder for viruses to be introduced in a thin client environment, and security can be enhanced greatly through adding levels of encryption," explained Hee.
Thin clients can also offer smart card functionality that restricts physical access to the desktop, providing an additional security layer. "Users can also access their individual computing sessions from any appliance in the workgroup, because the session resides on the server and is accessible up instantly with the insertion of a smart card or a password," said Donald Chen, consulting manager, Product Technology, Sun Microsystems.
Given the developments in thin client technology, vendors and resellers are understandably upbeat about thin client systems being able to replace traditional desktops wholesale. "If you're going to go thin client, do it for the whole desktop," said Steve Kaplan, a vice president and general manager at U.S.-based Citrix reseller Vector ESP. "Sure, you can make exceptions, but for the most part, go thin client everywhere." He added that the biggest mistake was to put in the infrastructure but then only use it for a couple of applications.
The startup costs can also be quite high. "Old desktops need to be retired generally all at the same time for the easiest installation, and new clients and servers need to be installed all at the same time," explained Gilliland. "Add to this the increased bandwidth requirements from the network, depending on the software used, and the initial investment can be prohibitive especially when chief information officers (CIOs) are being asked to show immediate return-on-investment (ROI) on their investments today."
"The need for powerful central servers, storage, and multiple broad channel bandwidth restricted the adoption of thin client technology," agreed K. C. Phua, product manager, Microsoft Singapore. However, he added that demand for broad bandwidth would increase as applications became "richer" compared to "green screen" thin clients of yesteryear.
Some vendors also acknowledged that they have to contend with entrenched attitudes toward the ROI from thin client systems. "Enterprise customers are conservative and they are slow to change their desktop buying patterns," remarked Hee of Citrix. "Coupled with the availability of low cost PCs, the initial purchase price of a thin client does cause some customers to hesitate."
"Many companies are still very PC-centric," agreed Chen. "Even though they like the thin client computing model, companies feel that they are locked in by existing PC-based applications and they continue to pay high licensing fees for software and administration costs."
Why the hesitation to go thin client? Besides legacy issues, one reason could be that thin clients don't fit every situation. For example, they cannot support compute-intensive or graphics-intensive applications, so power users may need their own desktop systems after all. Another reason could be the necessity for connectivity - there's no access to applications if the network goes down, although contemporary thin client software sports sophisticated load-balancing features to optimize backend server performance.
Still, the promises from thin client computing will become increasingly salient to users as the technology matures, bandwidth connectivity and reliability escalates and wireless devices become more powerful. A selective and fairly cautious approach towards thin client adoption seems to be the trend moving forward. Gilliland estimates that, through 2005, fewer than 2 percent of midsize and large enterprises will switch all their desktop applications to thin clients. At the same time however, at least 75 percent of enterprises will deploy thin client technology in some selected environments for targeted applications, for example, task-oriented end user environments such as customer service centers.
The motivators behind thin client computing continue to hold promise for the future. "What has changed is the notion of the client device," affirmed Peter Thomas, director of 9i Marketing, Oracle Asia Pacific. He acknowledged that while the concept of specialized thin client computers had yet to really take off, "the ideas driving them have been a success". According to Thomas, Web-enabled applications have helped drive down costs for customers, and revolutionized the enterprise applications market, with every major enterprise applications vendor providing a Web-enabled version of their products in response to customer demand.
Phua pointed to four main areas of technical developments in thin client computing - the availability of very scalable powerful server platforms, affordable bandwidth, thin client devices and thin client powered software that can handle common communication standards like SOAP (simple object access protocol), XML (extensible markup language), flash memory, device standards like Telnet, WMI and RDP.
Gilliland however felt that software was the key to the future of thin client technology. "Very little technology in the thin client arena is based around hardware," he explained.
Chen of Sun took another view. "The primary focus in enterprise computing has shifted away from hardware, software and applications towards network services," said Chen. "Today's service-driven network is modular, dynamic and based on Internet standards that make network services available to any user, anytime, from anywhere, using virtually any device."
Thin may soon be in.