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About NC
1 What is NC
NC, NETWORK Computer (NetWork Computer) Abbreviation. Since the 1995, since this idea, the network computer evolve into a broad concept and is not very accurate. Overall, the network computer belongs to a thin client. As Li Guojie said, the network computer is a type of network device between dumb and PCs, or it can be called Network Client. There is a wide "spectral line" between dumb and PCs, with great development space, in the field of specific applications, limited functional applications where there will be good market prospects.
The network computer can complete some local calculations, but it does not need to have a PC so strong processing power. The network computer is based on the network. It is not like a PC to work separately. To rely on server computing power and storage resources, it must be connected to it to provide application services and provide data storage spaces over the network, so network The computer is a system concept. In general, the network computer system is a "thin client / server" architecture, composed of network computers, servers, and necessary network devices, each part into a whole through the network protocol and terminal application protocol.
Ø CPU can use domestic CPUs, such as dragon core, square boat, north big public863, etc.
Ø Local Storage You can use a variety of storage media, such as DOC, DOM, 2.5 吋 HDD or CF card.
Ø The operating system generally uses embedded Linux. There are also Windows CE, Windows XP Embedded, and so on.
Ø Network protocol support TCP / IP, PPP, DHCP, DNS, etc.
Ø Support Terminal Protocol includes Microsoft RDP, Citrix ICA. XDMCP.
Ø The upper application web browser, the media player.
From the hardware configuration, NC generally has no local hard drive, and other components are similar to PC. For example, the configuration of China Tianyi network computer hardware, including CPU, memory, network card, keyboard, mouse, display, USB interface, etc., can be extended to configure serial port, parallel port, IC card, wireless network interface. This hardware configuration is basically equal to the I / O device such as the local hard disk, optical drive, and floppy drive from the PC. Of course, its various components are less cheap than the general PC. NC is low power, no cooling fan, for example, the power consumption of Northern Northern NC is less than 15 watts. The operating system of Shenzhou Tianya NC uses the clipping Linux, and the GUI is based on X Window, and the web browser is your own customized browser. Media play, mainly using the client CPU processing power.
As a system, the NC is essentially a considerable part of the computing task to handle it to the server, so the hardware requirements of the client are not high, and the customer's hardware cost will naturally fall. However, for the media to play this graphic intensive application, completely handle it to the server to do it, such as the application scenario of the electronic classroom, there is a large number of users in use, so there is only to calculate the calculated processor. Even if the network browsing, the amount involved is not small, the machine that can run the browser is not low. Therefore, the application scenario determines that the configuration of the NC is between the dumb and the PC, which is simpler, cheap, low-cost, cheap.
NC take centralized management and configuration, making maintenance work easier. Terminal client generally does not need to upgrade, whether it is hardware upgrade, or software upgrade, just complete it on the server. Users cannot easily destroy the system configuration.
2 NC application field
It is generally believed that network computers should be easily accepted by the government because of the low cost and safeguarding the safety of storage data, and improve employee efficiency. For example, for the company, because the network computer uses a centralized operation, all the information is placed on the server, so important data data is not taken. From current practical applications, network computers are not targeted in household computer markets, the scope of application is concentrated in the fields of enterprises, e-government, electronic classrooms. In these specific areas, architectures with network computers are very successful. For example, there are more than 50% of the top 100 companies in the United States using NC products from Huizhi (WYSE). In contrast, domestic enterprises have to be improved on NC acceptance. 3 NC can do, what can't be done
NC can support multiple working modes. Take the NC product in the Northern Duzhong as an example:
N WBT Terminal Model: A Windows NT / 2000 server based on RDP protocol can be supported.
N X-Terminal Mode: A UNIX server that connects to XDMCP protocols can be supported.
N C / S and B / S mode: Run the Client program or browser program on the NC, working with the server, and processing power can be shared.
N PC Mode: Access to your hard drive to support the complete Linux file system, you can get normal office and entertainment functions from the server and network.
It seems that the computing model of the network computer is, regardless of the supported protocol standards, or from the actual product, it is more mature, no new intention.
There are many problems involved in the network computer, such as the application's load balancing, dynamic binding of resources, and the dynamic migration of applications, are not considered in the network computer.
4 NC benefits
The benefits of NC are reflected in comparison with the program mainly constructed by the PC.
N low price. Under the premise of meeting the application needs, it reduces the overall cost of the system.
n centralized. Management and maintenance are more convenient.
n Close. There is no hard drive, floppy drive, optical drive, etc. to ensure the safety of enterprise data.
n By using domestic CPU chips, open source Linux operating systems, to some extent ensure that the system is more secure, such as e-government environment.
5 NC promotion
First, the price is still high. Under the trend of the brand PC, the NC is not a significant advantage than a low-end desk PC, which will reduce the market competitiveness of NC. For example, the Lenovo NET is NC, the media offer is about ¥ 2500 (free of the display).
Second, the first in the PC mode is mainly. NC appeal centralized application, not a replacement of PC, but a supplement to the PC. But this supplement is a traditional PC network system that has been formed, and how much development space is also worth studying, domestic users, has become accustomed to the freedom of PC. In addition, the old users change the investment perspective, and make a huge upgrade update, and it needs to be fake.
Third, the problem of operating the system. NC products, if Linux is supported as a core system, which affects the usage habits of some users. In addition, there is a platform for NC products based on the Windows operating system, which cannot be completely "independent". This is subject to a Windows system, which is not a very favorable factor on its future development, upgrade environment.
6 Characteristics and application scenarios of several computing modes
6.1 Traditional "Host - Terminal" mode
This mode is completely centralized. All calculations and storage are placed on the central server. The role of the terminal is just responsible for interaction with the user, including keyboard input, and character interface display capabilities, and terminals don't need other things. It is for "dumb". This is a reasonable mode in the large machine era, and there is no more choice, because the hardware price is high, the computing capacity is concentrated on a few large machines, centralized calculations, centralized storage, and terminals. Dumb is "the most thin". The cost of the character dumb terminal is low, which is small for network bandwidth requirements. It is safe. It can be used for long periods of use, so it is still useful in window business applications such as finance. Application premise of dumb terminal mode is that the computer's I / O speed is much slower than the CPU running speed. For now many applications, individual servers provide processing capabilities are often insufficient to cope with numerous terminal applications.
6.2 PC
PC has relatively powerful processing capabilities, memory resources, local storage, network I / O. PC small but complete, self-made system. This configuration of the PC is in line with its application characteristics. For example, household PCs need to meet document processing, web browsing, image, and audio and video processing and play, games. These applications, especially media and games, have higher requirements for the hardware configuration of the system.
6.3 C / S mode
In the 1980s, with many manufacturers such as IBM, many manufacturers have a good computing power, and the price can be accepted by the mass market, and the situation in the large-scale centralized computing mode is also moved. Many people can have a PC belonging to their own personal, and there is no need to compete for the limited CPU resources of those server hosts. And some of the disadvantages of centralized computing mode are also exposed, and it can be thought of, and the PC has certain computing power, then why can't I make full use of this part of the computing resources? Push all computational pressure to the server, making it a good way to become a bottleneck of the entire system. So this time the PC workstation deployment scheme in the Fat Client / Thin Server structure mode has arrived in the brilliant period. In particular, communication technology and computers have been combined and rapidly developed, causing computer network interconnection technologies and intended to make this calculated calculation model in the computational work.
7 NC primary manufacturers and products
7.1 major manufacturers
N Shenzhou Tianwei http://www.skyvein.com.cn/
N North Big Zone http://www.mprc.cn/
N Tsinghua SOPCA http://www.sopca.com.cn / ...
N Lenovo Netarem http: //appserver.lenovo.com.cn / ...
N Shenzhou Digital DNC http://www.digitalChina.com / ...
N Great Wall Network NC http://www.greatwall.com.cn / ...
NHHD Star nc http://www.itep.com.cn / ...
N 智 winterm http://www.wyse.com / ...
7.2 Winterm
United States, Wyse, the world's largest network computer manufacturer, one year of shipments account for more than 50% of the global market. Huizhi's product Winterm series is Windows-Based Terminal (WBT).
