To reduce the total cost of
computing ownership, an organization needs to leverage on everything that’s there in its
current computing infrastructure-hardware, applications, network and training.
Faced with an ever-changing
computing environment, IT professionals need to improve the efficiency of
business-critical application deployment. And all of this must be accomplished alongwith:
Managing and supporting users in a
timely and cost-effective manner.
Extending access to business-critical applications to dispersed users-regardless of
connection, location or device.
Ensuring exceptional application performance.
Providing right security for enterprise-level computing.
These challenges have made
enterprise-wide application deployment more daunting. The reason being that the products
developed to this point address only one, or possibly two, of the following obstacles:
MANAGEMENT: From a management
perspective, traditional enterprise application deployment is often time consuming,
expensive and difficult to manage. Not only do administrators have to physically
distribute applications to every client, but they also have to deal with version control
issues, remote support, multiple system configurations and data replication. When
confronted with thousands of users, the cost of application ownership may spiral out of
ACCESS: Today’s corporate computing
landscape comprises a heterogeneous mix of desktop devices, network connectivity and
operating systems. Access to vital Windows-based applications is difficult-or in the case
of internet/intranet computing, nonexistent-and often involves costly upgrades,
problematic emulation software and complete application rewrites.
PERFORMANCE: Most corporate
applications today are designed for high-bandwidth networks and powerful desktop
computers. This type of application design puts tremendous strain on congested corporate
networks and yields poor performance over lower-bandwidth, remote connections. Due to
this, many users simply avoid using the vital applications and data to get their work
done. When this happens, redundant work and significant decreases in productivity are
often the result.
SECURITY: Security is also a
challenge, because in traditional client server architectures, business-critical
applications and data live on both the server and the client desktops spread throughout
the world. Not only this increases the risk of unauthorized access, but also the risk of
lost or stolen information.
How to overcome
One way to overcome these obstacles
can be server-based computing. It is a model in which applications are deployed, managed,
supported and executed entirely on a server. It uses a multi-user operating system and a
method for distributing the presentation of an application’s interface to a client device.
With server-based computing, client
devices, whether ‘fat’ or ‘thin,’ have instant access to business-critical applications
via the server-without application rewrites or downloads. This means improved efficiency
when deploying business-critical applications. In addition, server-based computing works
within the current computing infrastructure and current computing standards and with the
current and future family of Windows-based offerings.
How server-based computing works?
The server-based computing model
employs three critical components. The first is a multi-user operating system that enables
multiple concurrent users to log on and run applications in separate, protected sessions
on a single server. The second is a computing technology that separates an application’s
logic from its user interface, so only keystrokes, mouse clicks and screen updates travel
the network. As a result, application performance is bandwidth-independent. The third key
component, centralized application and client management, enables large computing
environments to overcome the critical application deployment challenges of management,
access, performance and security.
Server-based computing is made
possible by two Citrix technologies: Citrix Independent Computing Architecture (ICA) and
Citrix MultiWin. The ICA protocol shifts application processing from the client device to
the server. MultiWin, the technology licensed by Citrix to Microsoft to jointly create
Terminal Server, enables multiple users to simultaneously access applications running on a
What is ICA?
ICA is a Windows presentation
services protocol from Citrix that provides the foundation for turning any client
device-‘thin’ or ‘fat’ into the ultimate thin client. The ICA technology includes a server
software component, a network protocol component and a client software component.
On the server, ICA has the unique
ability to separate the application’s logic from the user interface at the server and
transport it to the client over standard network protocols like IPX, SPX, NetBEUI, TCP/IP
and PPP; and over popular network connections like asynchronous, dial-up, ISDN, frame
relay and ATM.
On the client, users see and work
with the application’s interface, but the full application logic executes on the server.
The ICA protocol transports key strokes, mouse clicks and screen updates over standard
protocols to the client, consuming less than 20 Kbps of network bandwidth. ICA allows only
keystrokes, mouse clicks and screen updates to travel through the network. As a result,
applications consume just a fraction of the network bandwidth usually required.
Server-based computing Vs network
While all three computing models
have a valid role in today’s enterprises, it’s important to note the differences between
them. In the traditional client server architecture, processing is centered around local
execution using ‘fat’, powerful hardware components. In the network computing architecture
as defined by Sun, Oracle, Netscape, IBM and Apple, components are downloaded from the
network in to the client device for execution by the client. But with Citrix server-based
computing approach, users can access business-critical applications-including 32-bit
Windows-based and Java applications-without requiring them to be downloaded to the client.
This approach also provides considerable total cost of application ownership savings since
these applications are centrally managed and can be accessed by uses without having to
rewrite them. The server-based computing delivers both host computing and personal
HOST COMPUTING: Single-point
Physically and technically secure
Predictable ownership costs
Universal application access.
PERSONAL COMPUTING: Thousands of
Low-cost and fast-cycle application development
Graphical, rich data and easy to use
Wide choice of device types and suppliers.
What is a WBT?
A Windows-Based terminal (WBT) is a
thin-client hardware device that connects to Citrix server-based system software. Since
the applications it accesses are installed on the server, a WBT is not the equivalent of a
PC with its operating system and array of local applications. Nor is it interchangeable
with a network computer or NetPC, because these devices download and run applications off
The key criteria that distinguishes
WBTs from other thin-client devices, such as NCs or NetPCs, is that there is no
downloading of the operating system or applications, and there is no local processing of
applications at the client. All executing of the application logic occurs on the server.
WBTs have the following characteristics:
An embedded operating system such as
DOS, Windows CE or any real-time operating system.
ICA or Microsoft Remote Desktop Protocol (RDP) presentation services protocol to transport
keystrokes, mouse clicks and screen updates between the client and server. Entire
server-based execution of application logic.
No local executing of application at
the client device.
A WBT may incorporate third-party emulation software such as X, 3270 and 5250 for
connection to other host systems.
The ‘thinness’ of a WBT and the
various benefits of server-based computing make these thin clients ideal for certain types
of workers and market segments. For example, task-based employees which primarily works
with line-of-business applications, such as order entry, would be ideal candidates for a
WBT. Retail organizations operating point-of-sale terminals, and branch locations of banks
and stores, are markets that are also rapidly adopting these thin clients. WBTs are also
well suited for existing ‘green screen’ terminal users moving to a Windows environment.
Benefits of server based computing
Bring server-based computing to
heterogeneous computing environments providing access to Windows-based
applications-regardless of client hardware, operating platform, network connection or LAN
Offers enterprise-scale management
tools to allow IT professionals to scale deploy, manage and support applications from a
Provide seamless desktop integration
of the user’s local and remote resources and applications with exceptional performance.
Server-based computing solution
With server-based computing,
customers can increase productivity and develop a competitive advantage by gaining
universal access to business-critical applications they need to operate successfully. This
is regardless of the connection, location, or operating systems they may be using.
The following solution scenarios
demonstrate how server-based computing can help customers overcome the challenges of
enterprise-wide application deployment:
BRANCH-OFFICE COMPUTING: This is for
manageable, secure application deployment and access over corporate WANs.
PROBLEMS: To serve and support
customers in a better way, many enterprises are opening branch offices. However, this is
creating difficulties for administrators who lack resources to adequately staff these new
offices. One such problem is database replication. Many times, individual LANs are built
for each branch office. Configuring and managing these branch-office LANs-and the
information on them-creates numerous management challenges. Another problem is application
performance. Since most branch offices are connected by WANs to headquarters, vital data
and applications must travel back and forth across the network. This type of set-up
creates numerous user delays and unacceptable application response. Previously, the only
option was a bigger WAN connection, which meant increasing costs, not just once, but on an
SOLUTION: Server-based computing is
a better solution because it minimizes network traffic, even for Windows-based, 32-bit
applications. This approach allows applications to be deployed, supported and managed from
a central location.
CROSS-PLATFORM COMPUTING: This is
for windows-based application deployment to non-Windows desktop users.
PROBLEMS: In today’s era of global
consolidation, many enterprises are buying and merging new companies into their
organizations, as well as adding their own new employees and locations around the world.
Typically, this has resulted in a widely diverse set of client devices, operating systems,
processing power and connectivity options across the enterprise.
For IT professionals, trying to
leverage existing technology investments while deploying business-critical applications-
especially the latest 32-bit Windows-based applications-for all users has become more
difficult. As a result, organizations have to resort to using problematic emulation
software, purchase additional hardware and invest in costly application rewrites.
SOLUTION: Server-based computing is
a better, more cost-effective solution because it enables virtually any existing device in
the enterprise to access Windows based applications without special emulation software,
changes in system configuration or application rewrites. This means that enterprises can
maximize their investment in existing technology and allow users to work in their
preferred computing environments.
WEB COMPUTING: It allows remote
users to access full-function Windows-based applications from web pages.
PROBLEM: Web computing is taking
off. But to deploy interactive applications on an intranet or the internet, application
development is required. The Java applet ‘download-and-run’ model is not an extension of
any current computing technology. New software and, often, new hardware are required to
successfully deploy these solutions. Every time the application changes, the web-based
application needs to change as well. l
SOLUTION: Server-based computing
enables administrators to launch and embed corporate Windows-based applications into HTML
pages without rewriting a single line of code. Plus, it eliminates the need to manage and
maintain two separate sets of code.
REMOTE COMPUTING: It gives
high-performance, secure access to business-critical applications over remote, dial-up
PROBLEMS: The changing work
environment is allowing increasingly more employees to work away from the office-at home,
hotels, customer locations etc. This means that a wide variety of network connections are
being used to access corporate applications. Unfortunately, the lower the bandwidth, the
lower the application performance. Due to this, many remote users are avoiding corporate
applications altogether, as they’d rather work than wait.
Another factor is application
management and support for remote users. Administrators are forced to spend enormous time
trying to diagnose and correct problems over the phone. Unfortunately, the problems are
usually not resolved in the first time.
SOLUTION: Server-based computing
works better for remote users because it keeps all application processing on the server.
Meaning, less traffic is sent across the network. Plus, it’s optimized for low-bandwidth
connections so that users can get LAN-like performance over analog or ISDN modems, WANs,
wireless LANs and even the internet.
By eliminating the need for on-site
staff, server-based computing also makes it easier for administrators. They can deploy and
manage vital applications and support remote users-all from one location.
THIN-CLIENT DEVICE COMPUTING: In
this, Windows-based applications can be extended to newer, low-cost devices.
PROBLEMS: Traditional mini and
mainframe computing deliver some of the ‘centralized computing’ benefits as server-based
computing. Since these types of machines were not designed for the thousands of GUI-based
Windows applications that are available today. Furthermore, users on these types of
machines are familiar with text-based interface and are typically slow to adopt new
Also, many of today’s new
devices-like windows-based terminals, PDAs, wireless tablets, and information
appliances-are not compatible with the Windows-based, business-critical applications being
used in the enterprise unless rewrites are performed.
SOLUTION: With server-based
computing, the latest Windows-based programs can be extended to these thin devices without
application rewrites. This enables users to work in their preferred environments and still
access the Windows-based applications they need to work successfully. Plus, organizations
can reap the benefits resulting from reduced overhead, lower acquisition costs and fewer
Courtesy: Citrix Systems