Low Bandwidth X
Encyclopedia
In computing
, LBX, or Low Bandwidth X, was a protocol to use the X Window System
over network
links with low bandwidth
and high latency
. It was introduced in X11R6.3 ("Broadway") in 1996, but never achieved wide use. It was disabled by default as of X.Org Server
7.1, and was removed for version 7.2.
X was originally implemented for use with the server
and client
on the same machine or the same local area network
. By 1996, the Internet
was becoming popular, and X's performance over narrow, slow links was problematic.
LBX ran as a proxy server
(lbxproxy). It cached commonly used information — connection setup, large window properties, font metrics, keymaps and so on — and compressed
data transmission over the network link.
LBX was never widely deployed as it did not offer significant speed improvements. The slow links it was introduced to help were typically insecure, and RFB
(VNC) over a secure shell
connection — which includes compression — proved faster than LBX, and also provided session resumption.
Finally, it was shown that greater speed improvements to X could be obtained for all networked environments with replacement of X's antiquated font system as part of the new composited graphics system, along with care and attention to application and widget toolkit
design, particularly care to avoid network round trips
and hence latency
.
Computing
Computing is usually defined as the activity of using and improving computer hardware and software. It is the computer-specific part of information technology...
, LBX, or Low Bandwidth X, was a protocol to use the X Window System
X Window System
The X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...
over network
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
links with low bandwidth
Bandwidth (computing)
In computer networking and computer science, bandwidth, network bandwidth, data bandwidth, or digital bandwidth is a measure of available or consumed data communication resources expressed in bits/second or multiples of it .Note that in textbooks on wireless communications, modem data transmission,...
and high latency
Lag
Lag is a common word meaning to fail to keep up or to fall behind. In real-time applications, the term is used when the application fails to respond in a timely fashion to inputs...
. It was introduced in X11R6.3 ("Broadway") in 1996, but never achieved wide use. It was disabled by default as of X.Org Server
X.Org Server
X.Org Server refers to the X server release packages stewarded by the X.Org Foundation,which is hosted by freedesktop.org, and grants...
7.1, and was removed for version 7.2.
X was originally implemented for use with the server
Server (computing)
In the context of client-server architecture, a server is a computer program running to serve the requests of other programs, the "clients". Thus, the "server" performs some computational task on behalf of "clients"...
and client
Client (computing)
A client is an application or system that accesses a service made available by a server. The server is often on another computer system, in which case the client accesses the service by way of a network....
on the same machine or the same local area network
Local area network
A local area network is a computer network that interconnects computers in a limited area such as a home, school, computer laboratory, or office building...
. By 1996, the Internet
Internet
The Internet is a global system of interconnected computer networks that use the standard Internet protocol suite to serve billions of users worldwide...
was becoming popular, and X's performance over narrow, slow links was problematic.
LBX ran as a proxy server
Proxy server
In computer networks, a proxy server is a server that acts as an intermediary for requests from clients seeking resources from other servers. A client connects to the proxy server, requesting some service, such as a file, connection, web page, or other resource available from a different server...
(lbxproxy). It cached commonly used information — connection setup, large window properties, font metrics, keymaps and so on — and compressed
Data compression
In computer science and information theory, data compression, source coding or bit-rate reduction is the process of encoding information using fewer bits than the original representation would use....
data transmission over the network link.
LBX was never widely deployed as it did not offer significant speed improvements. The slow links it was introduced to help were typically insecure, and RFB
RFB Protocol
RFB is a simple protocol for remote access to graphical user interfaces. Because it works at the framebuffer level it is applicable to all windowing systems and applications, including X11, Windows and Macintosh...
(VNC) over a secure shell
Secure Shell
Secure Shell is a network protocol for secure data communication, remote shell services or command execution and other secure network services between two networked computers that it connects via a secure channel over an insecure network: a server and a client...
connection — which includes compression — proved faster than LBX, and also provided session resumption.
Finally, it was shown that greater speed improvements to X could be obtained for all networked environments with replacement of X's antiquated font system as part of the new composited graphics system, along with care and attention to application and widget toolkit
Widget toolkit
In computing, a widget toolkit, widget library, or GUI toolkit is a set of widgets for use in designing applications with graphical user interfaces...
design, particularly care to avoid network round trips
Round-trip delay time
In telecommunications, the round-trip delay time or round-trip time is the length of time it takes for a signal to be sent plus the length of time it takes for an acknowledgment of that signal to be received...
and hence latency
Latency (engineering)
Latency is a measure of time delay experienced in a system, the precise definition of which depends on the system and the time being measured. Latencies may have different meaning in different contexts.-Packet-switched networks:...
.
See also
- dxpc The Differential X Protocol Compressor
- Virtual Network ComputingVirtual Network ComputingIn computing, Virtual Network Computing is a graphical desktop sharing system that uses the RFB protocol to remotely control another computer...
(VNC) - xmoveXmovexmove is a computer program that allows the movement of X Window System applications between different displays and the persistence of X applications across X server restarts. It solves a problem in the design of X, where an X client is tied to the X server it was started on for its lifetime...
- a tool allows you to move programs between X Window System displays - xpraXpraxpra or X Persistent Remote Applications is a tool which allows you to run X programs usually on a remote host and then direct their display to your local machine without losing any state. It differs from standard X forwarding in that it allows disconnection and reconnection without disrupting the...
- a more recent tool which is similar to xmove - NX technologyNX technologyNX technology is a computer program that handles remote X Window System connections, 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...
, an X acceleration system