TightVNC 1.2.2, is it beneficial?

[Chris Jaecker]

At 06:00  10/02/02 +0000, you wrote:
>Date: Sat, 09 Feb 2002 09:53:31 -0500
>From: Shing-Fat Fred Ma <fma "at" doe.carleton.ca>
>Subject: Re: TightVNC 1.2.2, is it beneficial?
>
>I find tightVNC quite stable, and tight encoding is suppose to
>be more effective for pixels of greater than 8 bits.  But you would
>probably only using tight encoding over 56Kbps lines (which
>typically seem to operate at half that rate) because that's when
>it actually improves bandwidth rather than impede it.  However,
>even over DSL, I stick with 8 bits because some CAD tools
>crash when the solairs8 server starts up with 16 bits e.g. Cadence
>Signalscan Waves.  Yes, you have to muck around with the
>colors a bit to make them look sane, but on the upside, you get
>nice crisp contrast when the colors are quantized in such big
>steps.
>
>Fred
>- --------------------------------------------------------------------------
>Fred Ma
>Department of Electronics
>Carleton University, Mackenzie Building
>1125 Colonel By Drive
>Ottawa, Ontario
>Canada     K1S 5B6
>fma "at" doe.carleton.ca

Fred,

Just a quick clarification here:- 56k modems do not operate at 56Kbps, at 
least not bi-directionally. Modems in general convert digital information 
(bits) into analog (electrical representations of sound), and back. 
Operating properly, a 56K modem converts the bits from your computer into 
analog to cross your local loop (the two wires from your "telephone" to the 
telephone exchange) and then it is converted to digital signals at the 
local telephone exchange and delivered through the phone network to an ISDN 
Primary Rate interface at the other end. Throughput from your computer is 
at about 33.2Kbps. The data coming from the other end (which is a router or 
access server connected to an ISDN network) does not need to be converted 
from digital to analog because ISDN is digital. So data coming in from the 
other end is sent at 56kbps.

If you connect two 56K modems through the telephone system, they'll never 
go faster than 33.2Kbps, as they are both having to do the digital/analog 
conversions. Only when you connect to an ISDN device (e.g. at your ISP), 
will the traffic to you be sent at 56K. Any kind of noise or attenuation of 
signal will lower this of course.

So "about half" is actually "about right"...

Best wishes

Chris Jaecker
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