Being able to transfer files to and from the remote computer is a very handy feature especially when using the "Single Click" remote client module. This eliminates the need for emailing files to the client, and various other methods of file transfer. Complete Folders can be transfered between the viewer and server, add to this the fact that these files are compressed prior to transfer, and you get maximum flexability with minimal bandwidth.
It uses the current VNC connection and can be invoked any time. You can minimize the Chat window to allow screen updates and keep the text intact, to restore it later and continue the discussion. Developers are free to add additional encoding and security types but they must book unique identification numbers for these with the maintainers of the protocol so that the numbers do not clash. Clashing type numbers would cause confusion when handshaking a connection and break cross-compatibility between implementations.
The list of encoding and security types was maintained by RealVNC Ltd and is separate from the protocol specification so that new types can be added without requiring the specification to be reissued. A community version of the RFB protocol specification which aims to document all existing extensions is hosted by the TigerVNC project.
Since encodings are part of the negotiation, some of the encodings below are pseudo-encodings used to advertise the ability to handle a certain extension. Of the publicly-defined picture-based encodings, the most efficient ones are the Tight encoding types. Two types of encodings are defined by TightVNC:. It does become more efficient with fewer I-frames keyframes , but CPU utilization remains a problem. In terms of transferring clipboard data, "there is currently no way to transfer text outside the Latin-1 character set".
The VNC protocol is pixel based. Although this leads to great flexibility i. Those protocols send graphic primitives or high level commands in a simpler form e. This limits the number of mouse buttons to eight effectively 7 given convention of button 0 meaning "disabled". A "GII" extension solves this problem. From Wikipedia, the free encyclopedia. Computer network protocol.
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In this way, clients can run on the widest range of hardware, and the task of implementing a client is made as simple as possible. The display side of the protocol is based around a single graphics primitive: "put a rectangle of pixel data at a given x,y position". This might seem an inefficient way of drawing arbitrary user interface components. But because we have a variety of different encoding schemes for the pixel data, we can select the appropriate scheme for each rectangle we send, and make the most of network bandwidth, client drawing speed and server processing speed.
The lowest common denominator is the so-called raw encoding, where the rectangle is simply pixel data sent in left-to-right scanline order. All clients and servers must support this encoding. However, the encodings actually used on any given VNC connection can be negotiated according to the abilities of the server, the client, and the connection between the two.
The copy rectangle encoding, for example, is very simple and efficient and can be used when the client already has the same pixel data elsewhere in its framebuffer. The server simply sends an X,Y coordinate giving the position from which the client can copy the rectangle of pixel data. This means that operations such as dragging or scrolling a window, which involve substantial changes to the screen, may only require a few bytes. Most clients will support this encoding, since it is generally simple to implement and saves bandwidth.
A typical workstation desktop has large areas of solid colour and of text. Some of our most effective encodings take advantage of this by efficiently describing rectangles consisting of one majority background colour and 'sub-rectangles' of different colours. There are numerous other possible schemes. An encoding which uses some kind of caching of pixel data would be good for rendering text, where the same character is drawn in the same font multiple times.
Subsequent occurrences of the same character would be encoded simply by reference to the first occurrence. A sequence of these rectangles makes a framebuffer update or simply update. An update represents a change from one valid framebuffer state to another, so in some ways is similar to a frame of video, but it is usually only a small area of the framebuffer that will be affected by a given update.
Each rectangle may be encoded using a different scheme. The server can therefore choose the best encoding for the particular screen content being transmitted and the network bandwidth available. The update protocol is demand-driven by the client. That is, an update is only sent by the server in response to an explicit request from the client. This gives the protocol an adaptive quality. The slower the client and the network are, the lower the rate of updates becomes.
Each update incorporates all the changes to the 'screen' since the last client request. This also improves the apparent response speed. The input side of the protocol is based on a standard workstation model of a keyboard and multi-button pointing device. Input events are sent to the server by the client whenever the user presses a key or pointer button, or whenever the pointing device is moved. On our Videotile , for example, a pen-based handwriting recognition engine generates keyboard events.
Please consider supporting us by disabling your ad blocker. PcHelpWare and uvnc2me require XP or later. This common start point means that most of the VNC flavours available today "usually" talk nicely together, allowing for easy cross platform desktop sharing to occur. If you provide computer support, you can quickly access your customer's computers from anywhere in the world and resolve helpdesk issues remotely!
With addons like Single Click SC your customers don't even have to pre-install software or execute complex procedures to get remote helpdesk support. We are a small team of highly motivated and cool people :- Our goal is to make the more powerful, user-friendly and no-brainer free Remote Control software available. Contact: This email address is being protected from spambots.