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valium addiction The LBX Mini-HOWTO Paul D. Smith, psmith@baynetworks.com v1.04, 11 December 1997 LBX (Low Bandwidth X) is valium addiction n X server extension which performs compres sion on the X protocol. It is meant to be used in conjunction valium addiction ith X applications and an X server which are separated by a slow network connection, to improve display and valium addiction response time. ______________________________________________________________________ Table of Contents 1. valium addiction Introduction 2. What's The Status Of LBX? 3. Who Can Benefit From LBX? 4. Who Doesn't Need LBX? 5. How Do valium addiction s LBX Work? 6. What Do I Need To Use LBX? 7. What Don't I Need To Use LBX? 8. How Do I Start LBX? 9. Prob valium addiction ems 10. Documentation 11. Alternatives 11.1 dxpc - The Differential X Protocol Compressor 11.1.1 valium addiction Advantages 11.1.2 Disadvantages 11.1.3 Where Can I Get dxpc? 11.2 Ssh (Secure Shell) 11 valium addiction 3 Which Is Better? ______________________________________________________________________ 1. Introduction valium addiction Low-Bandwidth X (LBX) attempts to recognize that in this day and age, not everyone will be a fast LAN hop or valium addiction two away from the system that they are running their applications on. The X protocol can generate an extrao valium addiction dinary amount of traffic, especially for simple-seeming things such as creating new windows. As anyone who valium addiction has tried to use X over a dial-in modem at 28.8 or even higher can attest, creating new X windows can involv valium addiction an excruciating wait. LBX is fundamentally a compression and caching scheme designed to minimize the amou valium addiction t of X traffic generated between two systems. 2. What's The Status Of LBX? As of the X Consortium's releas valium addiction of X11R6.3 in December, 1996, LBX is a full extension to the X protocol. For XFree86 folks, that's XFree86 valium addiction version 3.3. 3. Who Can Benefit From LBX? If you use a modem to dial into a service provider, then run X valium addiction applications on remote machines with their DISPLAYs set to your local machine (or vice versa), LBX will spee valium addiction up that connection. Also if you set DISPLAYs from systems across WANs (other countries, for example) or o valium addiction her slow links, LBX can help. 4. Who Doesn't Need LBX? LBX is useless, of course, if you're only running a valium addiction plications locally, or if you're not running X at all. Also, if you're running on a fast LAN, LBX won't be valium addiction uch help. Some people say "if LBX cuts down on network traffic, wouldn't it be good to use even on fast LA valium addiction s?" It might be, if your goal is to reduce network traffic. But if your goal is to get better response tim valium addiction LBX probably isn't what you want. Although it does introduce caching and compression, that comes at a cos valium addiction on both ends (extra memory for caching, and extra CPU for decompression). If your link is fairly speedy L valium addiction X will probably result in an overall slowdown. 5. How Does LBX Work? LBX works by introducing a proxy serv valium addiction r at the client side, which performs caching and compression. The X server knows that the client is using valium addiction proxy server, and decompresses accordingly. Here's a normal setup for remote X clients. In our discussion, valium addiction LOCAL is always the workstation sitting in front of you, whose monitor you're looking at, and REMOTE is the valium addiction remote workstation, where the actual application is running. _________________________________________ valium addiction ____________________________ REMOTE LOCAL +-----+ valium addiction +-----+ | APP |-\ Network +----------+ | |\ valium addiction +-----+ \--------------------------->| X SERVER |=>| || +-----+ / (X Protocol) valium addiction +----------+ +-----+\ | APP |-/ /_____// +-----+ valium addiction ______________________________________________________________________ When using LBX, a proxy server (lbx valium addiction roxy) is introduced on the remote side, and the applications talk to that process instead of directly to th valium addiction LOCAL server. That process then performs the caching and compression of X requests and forwards them. It valium addiction ooks like this: ______________________________________________________________________ REMOTE valium addiction LOCAL +-----+ valium addiction +-----+ +-------+ Network +----------+ | |\ | APP |->| PROXY |----------------- valium addiction ----------->| X SERVER |=>| || +-----+ +-------+ (LBX/X Protocol) +----------+ +-----+\ valium addiction +-----+ / /_____// | APP |--/ +-----+ _______________ valium addiction ______________________________________________________ Details on exactly what caching and compression LBX d valium addiction es is beyond the scope of this document. 6. What Do I Need To Use LBX? You need an X server on your LOCAL valium addiction system which has the LBX extension compiled in. Unless you explicitly told it not to when building it, X11 valium addiction 6.3 servers automatically enable LBX. Also, all XFree86 3.3 servers have LBX enabled by default. You can u valium addiction e the xdpyinfo command to see if your server has the LBX extension: run xdpyinfo and look at the list just u valium addiction der "number of extensions"; you should see "LBX" listed there. Next, you need to get an lbxproxy program co valium addiction piled for the REMOTE system. This is the tricky part. If the remote system is not the same type as your l valium addiction cal system, the lbxproxy on your local system will do you no good, of course. There is unfortunately no "broken out" distribution of lbxproxy, so you will have to either (a) get and build most, if not all, of X11R6.3 for the remote system, or (b) find someplace to get a pre-compiled lbxproxy binary for your system. The latter is much simpler of course. The lbxproxy is simply a single executable. There are no configuration files, resource files, etc. associated with it. 7. What Don't I Need To Use LBX? The REMOTE system does not need a new X server (as always, the REMOTE system doesn't need any X server running). The application you want to run does not need to be linked with any special version of X, or any special libraries; I regularly use commercial X11R5 apps over LBX with no trouble. You do not need root or other privileged access on the REMOTE system; the lbxproxy process runs under your normal access permissions. Further, you can run it right fr
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