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NX technology, produced by NoMachine,〔.〕 is a computer program that handles X Window System connections to display remote desktop environments over a computer network, and attempts to greatly improve on the performance of the native X display protocol to the point that it can be usable over a slow link such as a dial-up modem. It wraps remote connections in SSH sessions for encryption. The NX scheme was derived from that of DXPC – the Differential X Protocol Compressor project.〔.〕 NX software is currently available for Windows, Mac OS X, Linux, and Solaris. NoMachine has clients available for Windows and Mac OS X, and Google makes a freely available Open Source GPL2 version of the server called Neatx. == Technical details == NX compresses the X11 data to minimize the amount of data transmitted. NX takes full advantage of modern hardware by caching all manner of data to make the session as responsive as possible. For example the first time a menu is opened it may take a few seconds, but on each subsequent opening the menu will appear almost instantly. NX is faster than its predecessors, as it eliminates most of the X round trips, while dxpc and MLView only compress data. The two principal components of NX are nxproxy and nxagent. nxproxy is derived from dxpc and is started on both the remote (client in X terminology) and the local (server in X terminology) machines simulating an X server on the client and forwarding remote X protocol requests to the local X server. Simplest Setup: remote clients (xterm, etc.) ↕ nxproxy client ↕ Network ↕ nxproxy server ↕ local X server (monitor/keyboard) nxproxy alone achieves 1:10 to 1:1000 compression ratios〔.〕 reducing bandwidth, but does not eliminate most of X's synchronous round trips, which are mostly responsible for X's perceived latency. nxagent in turn is derived from Xnest and is typically started on the remote (client) machine, thus avoiding most X11 protocol round trips. Together with nxproxy (which is built into nxagent) this setup performs well over low bandwidth/high latency links: Typical Setup:〔 remote clients (xterm, etc.) ↕ nxagent server side \ nxagent client side nxagent executable nxproxy client / ↕ Network ↕ nxproxy server ↕ local X server (monitor/keyboard) On systems with a functional X11 implementation, nxproxy and nxagent are all that is needed to establish a connection with low-bandwidth requirements between a set of remote X clients and the local X server. SSH can be used to establish a secure tunnel between the two hosts involved. FreeNX and the various NX Clients are used for setup, handling suspend and resume, secure tunnelling over SSH, and for printing and sound. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「NX technology」の詳細全文を読む スポンサード リンク
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