Thin client base solution

“Thin clients” are workstations connecting to terminal servers used to run all actual applications.
The main goal of such approach is to reduce TCO (total cost of ownership). The reduction of expenses is achieved by reduction of hardware costs and improvement of administrative efforts to maintain the system.

Where can thin clients be used?

Thin clients can be used everywhere where a big number of users work on similar office or specific tasks, which do not utilize all hardware capabilities of powerful PCs. These are workstation of operators, office terminals, classes, cyber-cafes.
From the user perspective thin client is mini-device with power on/off button and slots for plugging display, mouse, keyboard and network cable. The device does not contain a hard drive, floppy drive or CD/DVD drive which results in increased robustness, reduced power consumption and noiseless operation.
The solution has the following advantages:

• Reduced expenses, protection of deposits;
• Robustness;
• Data storage security;
• The ease of administration;
• Remote accessibility;
• Effective usage of hardware resources and reduced power consumption;
• Ergonomic workstations.

Server-side requirements

A robust and high performance server (or servers) is required to guarantee efficient usage of the solution. It would require certain initial investments and would cost major part of the solution budget. The server should provide sufficient performance to allow multiple thin clients connect and use multiple applications on it simultaneously. However performance requirements are not in linear dependence on the number of concurrent users. In the majority of use case scenarios (like several users running MS Office applications) OS will cache libraries and other files used by the applications in memory, so starting the applications will not require hard disk operations and as result the applications will start faster. However the relatively high cost of server-side hardware is completely compensated by low cost of client-side equipment.
On a side note, a good deal of attention should be paid to robustness of the server-side hardware since any server failure would result in client terminals unable to work.
Several other requirements need to be identified for the solutions to work efficiently. These are, for example, network bandwidth requirement and definition of use case scenarios.
The advantages of thin clients make them attractive for various companies – the solution just needs to be well-tuned for specific company tasks. One of the most important aspects is significant reduction of total cost of ownership of this solution compared to traditional approach when each workstation is based on high performance PC hardware. Gartner Group estimates TCO reduction by 5-40% depending on the company needs and specifics. It’s necessary to understand that TCO does not only consist of hardware costs, but it also includes administrative effort, hardware updates, risks of hardware malfunction, etc. Microsoft Windows 2008 Server, Microsoft Windows 2003 Server, Citrix Metaframe 1.8 can be used as software for the server-side part of the solution depending on the specific needs. Each of the servers has certain advantages and disadvantages, so the choice depends on the specific needs.

Advantages of solution with thin client

• Reduced expenses;
• Terminal hardware does not need upgrading;
• Terminals do not include expensive hardware;
• Reduction of TCO;
• Reduction of maintenance time;
• Mission critical data is never lost due to terminal malfunction;
• Ease to replace terminals in cases of hardware malfunction;
• Reduced power consumption (a terminal can save up to 80% of power used by ordinary desktop workstation)

Robustness

• Longer hardware lifetime. Absence of mechanical components in client terminals and simplified architecture rises robustness of the entire solution compared to traditional desktop workstations.
• Terminal malfunction will never cause loss of data since all data is stored on server.
• Increased security. Absence of hard, floppy and CD/DVD drives mitigates risk of information leaks and virus attacks.
• Actual data is not transferred over network – RDP protocol used for client-server communication transfers only screenshots of the remote sessions. RDP is encrypted protocol and can be encrypted with stronger encryption programmatically to guarantee data from being intercepted and decrypted.
• Centralized data storage dramatically simplified data backups and removes the need to monitor and backup sensitive data on multiple client PCs.

Effectiveness of administration

• Increased effectiveness of administration reduces maintenance expenses.
• In terminal server environment the administration is completely centralized.
• Improved, simplified and centralized control of software used within the company.
• Control of user activities and prevention of undesired actions.

Remote access

• Users can connect to their personalized and configured environment from any location in the world. The only requirement is Internet connection or other WAN/LAN access to the server.
• The reduced network workload, since users only receive images of remote desktop while in traditional environments they might need to send considerable amounts of data over networks.
• Ability to quickly and painlessly upgrade hardware to increase performance. Compared to traditional desktop workstations it takes to upgrade just server hardware to increase hardware resources of the company. No need to upgrade each individual PC.
• Performance improvement for distributed applications. Distributed applications residing on single physical hardware will operate faster in such environment.

Ergonomic office

• Noiseless operation. Thin clients do not have mechanic parts and even don’t need coolers.
• Thin client terminals are small in size and don’t exceed a size of a book. They are mobile and require minimal space.

Network bandwidth requirements

Client-to-server traffic does not exceed 1 kilobyte/second. Maximum traffic achieved in test mode was 1000 bytes/second. Server-to-client traffic normally does not exceed 10-20 kilobytes/second and depends on matter of images sent from server to client over network. When working with office documents it is about 5-6 kilobytes/second. Maximum traffic volume achieved during testing with quickly updating image-rich content is 106600 bytes/second. Such low traffic requirements are the results of compression and transition of differential parts of desktop images. If the required traffic exceeds network bandwidth, the connection does not drop – it only causes slightly slower response time. As result, low bandwidth networks with bandwidth even of 3-4 kilobytes/second can be used to access remote environment. Speaking about statistics, provided the network bandwidth of an Ethernet network gives 100 megabits/second, 20-30 users can work without any delays in the worst case scenario. Realistic estimation for “expected scenario” is about concurrent 400-500 users.

Recommendations for usage of solution based on thin clients

Decision of usage of thin clients should be based on the company needs. It is recommended for office and similar tasks like development, etc., but can be inefficient for other tasks. For example, it is inefficient for watching video or playing 3D video games, since these tasks will generate high network traffic and utilize server-side performance in too much and in an inefficient manner.