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Cal Poly |
Cal Poly 3801 West Temple Avenue Submitted By: Daniel Formel
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Title V Project
Server Based Computing
Thin Client Technology
Introduction
Server based computing is a logical evolution of todays networking environment that gives organizations a way to extend resources, simplify application deployment and administration, and lower the cost of ownership. The term thin client originated with a new generation of client devices that run "thin" operating systems locally as opposed to the traditional "fat" PC operating systems (Win95, NT, 2000, etc.). Most thin clients are powered by back-end central servers that are capable of serving all types of clients, fat and thin.
The fundamental philosophy behind thin client and server based computing is simple: instead of running applications locally on expensive PCs with all their inherent peripherals, moving parts, security and maintenance problems, run all applications on a powerful central server and simply communicate screen updates and keyboard/mouse commands with a thin client device. The network traffic is essentially screenshots, keystrokes, and mouse controls. The cost, security, and performance advantages are significant.
A thin client typically has the required client software pre-installed in FLASH memory allowing it to immediately connect to an application server running under the server based computing model. The embedded operating system (typically Windows CE or Linux) and remote presentation services protocol provide all the software required to enable users to run UNIX, Windows or Java applications from the connected server on the thin client.
Server based computing allows servers to keep application execution 100%, offering system administrators the ability to scale, deploy, manage and support applications from a single location. The thin client devices allow instant access to mission-critical applications on the server which can be load-balanced across multiple data centers.
Improving
Security with Thin Clients
Server based computing greatly enhances security in a network environment since critical applications and files are held on centrally-managed and controlled servers or databases. It also optimizes control of data and access, while eliminating entry points for viruses and data theft. So if a client is lost or damaged, the data is still available and secure.
Below is a list of benefits provided by thin client technology.
§
Virus
Resistant
Thin clients have no point of entry for locally introduced viruses since there is no local storage medium (i.e. hard drive or floppy drive). Hence, a thin client cannot become infected with a virus.
§
Data
Security
Since applications and files are centrally managed, data cannot be removed or altered unless specified by the system administrator.
§
Centralized
Management and Control
Server based computing gives system administrators the ability to manage corporate desktops or key applications centrally, resulting in significant support benefits. These include one stop upgrades, centralized control of back ups, anti-virus and licensing and enhanced support capabilities including the ability to control user sessions. Any hardening procedures will affect all users.
§
Downtime
Security
If an organization’s user computing environment was comprised or damaged, then the critical applications and files will remain unchanged. By simply replacing the thin clients with new ones, the computing environment will return immediately to operational status without installing new software. Also during the downtime, all data will remain protected on the central server.
Desktop PC vs. Thin Client
Besides the security benefits of thin client computing there are also several benefits to using thin clients over using standard desktop workstations.
|
Attribute |
Thin Client |
PCs |
|
Application software
management |
Centrally administered |
Must be maintained on each
desktop |
|
Useful life |
Over 5 years |
Less than 3 years |
|
Obsolescence factor / Upgrade
management |
Low: No hardware upgrade
required to run any new application |
High: next-generation applications
often require upgrade |
|
Software-hardware
interdependencies |
Virtually none |
High: hardware must be capable
of running application. |
|
Security: susceptibility to
data theft |
None. Data cannot be removed
(if specified by IT manager) |
Data removable via floppy
disk, zip drive, CDROM burner, Theft, etc. |
|
Security: virus susceptibility
|
None. No point of entry for
virus. |
Virus can enter via floppy
disk, email, Internet. |
|
Reliability |
No moving parts to fail. |
Disk drives, CDROM, fans, etc.
will eventually fail. |
|
Network bandwidth utilization
/ load predictability |
Low – 1/10th normal
‘Fat Client’ utilization. Highly predictable. |
Highly variable / difficult to
predict. 10 times more bandwidth required than for Thin Client. |
|
Effective computing power
available to each user |
Dependent on number of
concurrent users, power and number of servers, etc. |
100% of PC resources available
to user, though typically only 10% is used. |
|
Target users |
Task-based workers, point of
service, knowledge workers, public terminals, factory floor |
Power users, information
creators, traveling users, technical and graphical workers |
|
Purchase price |
Generally under $800 |
Corporate PCs generally over
$1500 |
|
Relative total cost of
ownership (TCO) |
Less than 63% |
100% |
*This table is from adtcom Network Computing
AG (http://www.adtcom.com/vendor/faq.htm)
Disadvantages
§ The central server has the responsibility to do most or all of the processing. Therefore resources such as CPU power and memory size must be concentrated on the server.
§ If the server goes down or is compromised then all users will be affected.
§ Limitations for multimedia applications.