Hello, after one week of running LTSP over compressed SSH the effects are predictable: - the network traffic is about 1/4 - the CPU load is double (of without compression; about same conditions)
We know NX, but we don't have any good experience with the support of 'NoMachine'. Second thing: NX costs much money (several thousands euro / year) witch we can save. That's why we stopped using NX, but we look forward and think about testing 'freenx'. I think our overall experience with compressed SSH is positive, but of course it depends on the situation. Greetings, Wojtek Ondrej Valousek schrieb: > I would say: > If is that the bandwidth what you are concerned about, go for NX. It is > based on ssh, but much better tuned for our main job - delivering remote > desktop... > Ondrej > > Rob Owens wrote: >> Interesting. This is from man ssh_config: >> >> CompressionLevel >> Specifies the compression level to use if compression is >> enabled. >> The argument must be an integer from 1 (fast) to 9 (slow, best). >> The default level is 6, which is good for most applications. >> The >> meaning of the values is the same as in gzip(1). Note that this >> option applies to protocol version 1 only. >> >> So maybe compression is just not adjustable in protocol 2, but can be turned >> on/off? >> >> -Rob >> >> On Thu, Feb 05, 2009 at 03:14:56PM +0100, Wojtek wrote: >> >>> Hello, >>> >>> I'm not so sure... >>> >>> From RFC4251 http://tools.ietf.org/html/rfc4251 : >>> >>> "The Transport Layer Protocol [SSH-TRANS] provides server >>> authentication, confidentiality, and integrity. It may optionally >>> also provide compression. The transport layer will typically be >>> run over a TCP/IP connection, but might also be used on top of any >>> other reliable data stream." >>> >>> >>> From RFC4253 http://tools.ietf.org/html/rfc4253#section-6.2 : >>> >>> "The following compression methods are currently defined: >>> >>> none REQUIRED no compression >>> zlib OPTIONAL ZLIB (LZ77) compression >>> " >>> >>> >>> So now I am even quite sure of the opposite... >>> >>> >>> The reason for this topic was some lecture about lbxproxy (R.I.P.), and >>> the conclusion of the developer: "The only useful changes to the wire >>> protocol are the use of lossless image compression within X or a full >>> wire-level compression proxy such as SSH underneath X." >>> >>> I think we'll try to compess the traffic. If we'll have some results, we >>> will send them for the discussion >>> >>> Greetings, >>> >>> Wojtek >>> >>> Rob Owens schrieb: >>> >>>> On Wed, Feb 04, 2009 at 06:29:35PM +0100, Wojtek Polcwiartek wrote: >>>> >>>>> Hallo, >>>>> >>>>> We watched the 'ps' output on the client and saw that the 'ssh'-process >>>>> starts without '-C' switch. The ssh_config file does not contain >>>>> anything about compression too. >>>>> We set the 'NETWORK_COMPRESSION=true' but nothing happened. >>>>> Does this option work? Any advices? >>>>> We use LTSP5/UbuntuHardy. >>>>> >>>>> >>>> I believe with ssh protocol 2 (the current protocol), compression is >>>> included by default and cannot be tuned or turned off. I don't have a >>>> link to prove it, but if you do some googling I think you'll find it to be >>>> true. >>>> >>>> -Rob >>>> >>>> ------------------------------------------------------------------------------ >>>> Create and Deploy Rich Internet Apps outside the browser with >>>> Adobe(R)AIR(TM) >>>> software. With Adobe AIR, Ajax developers can use existing skills and code >>>> to >>>> build responsive, highly engaging applications that combine the power of >>>> local >>>> resources and data with the reach of the web. Download the Adobe AIR SDK >>>> and >>>> Ajax docs to start building applications >>>> today-http://p.sf.net/sfu/adobe-com >>>> _____________________________________________________________________ >>>> Ltsp-discuss mailing list. To un-subscribe, or change prefs, goto: >>>> https://lists.sourceforge.net/lists/listinfo/ltsp-discuss >>>> For additional LTSP help, try #ltsp channel on irc.freenode.net >>>> >>>> >>> ------------------------------------------------------------------------------ >>> Create and Deploy Rich Internet Apps outside the browser with >>> Adobe(R)AIR(TM) >>> software. With Adobe AIR, Ajax developers can use existing skills and code >>> to >>> build responsive, highly engaging applications that combine the power of >>> local >>> resources and data with the reach of the web. Download the Adobe AIR SDK and >>> Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com >>> _____________________________________________________________________ >>> Ltsp-discuss mailing list. To un-subscribe, or change prefs, goto: >>> https://lists.sourceforge.net/lists/listinfo/ltsp-discuss >>> For additional LTSP help, try #ltsp channel on irc.freenode.net >>> >> ------------------------------------------------------------------------------ >> Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM) >> software. With Adobe AIR, Ajax developers can use existing skills and code to >> build responsive, highly engaging applications that combine the power of >> local >> resources and data with the reach of the web. Download the Adobe AIR SDK and >> Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com >> _____________________________________________________________________ >> Ltsp-discuss mailing list. To un-subscribe, or change prefs, goto: >> https://lists.sourceforge.net/lists/listinfo/ltsp-discuss >> For additional LTSP help, try #ltsp channel on irc.freenode.net >> > > > ------------------------------------------------------------------------------ > Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM) > software. With Adobe AIR, Ajax developers can use existing skills and code to > build responsive, highly engaging applications that combine the power of local > resources and data with the reach of the web. Download the Adobe AIR SDK and > Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com > _____________________________________________________________________ > Ltsp-discuss mailing list. To un-subscribe, or change prefs, goto: > https://lists.sourceforge.net/lists/listinfo/ltsp-discuss > For additional LTSP help, try #ltsp channel on irc.freenode.net > -- Wojtek Polcwiartek ------ tubIT TU-Berlin Web : www.tubit.tu-berlin.de Email : [email protected] Tel : +49.30.314.28000 ------------------------------------------------------------------------------ Create and Deploy Rich Internet Apps outside the browser with Adobe(R)AIR(TM) software. With Adobe AIR, Ajax developers can use existing skills and code to build responsive, highly engaging applications that combine the power of local resources and data with the reach of the web. Download the Adobe AIR SDK and Ajax docs to start building applications today-http://p.sf.net/sfu/adobe-com _____________________________________________________________________ Ltsp-discuss mailing list. To un-subscribe, or change prefs, goto: https://lists.sourceforge.net/lists/listinfo/ltsp-discuss For additional LTSP help, try #ltsp channel on irc.freenode.net
