On Fri, Jun 04, 1999 at 04:04:29PM -0300, Thomas T. Soares wrote:
> Hi there...
>
> Could anyone tell me what should be the transfer rate if I am
> downloading
> a compressed file (gzip -9) is I am connected as 31200 bps?
>
> I am getting about 3.6Kb/s but not sure if this is the best I can do
> and the ppp_deflate seems do no difference at all...
The data you are transfering is already of maximum entropy
kind, and that can't be compressed, no matter what.
TCP+IP frames are 40 bytes out of each 1500 bytes, or 2.7%,
and while those are compressible (possibly), compressing
already compressed data is bound to give fits to the adaptation
algorithm, and may cause it in the end just to send the raw
datablocks wrapped into some kind of frames taking up *more*
space, than the original data -- not much, but some..
You might get a bit better total throughput as calculated
per bytes of uncompressed file by using "bzip2 -9", and run
the link at modem level WITHOUT compression, like also at
the PPP level without compression! You *might* consider
use of VJ-header-compression, though.
All this sounds so counter-intuitive, does it not ?
> Thank you.
> --
> |Porto Alegre| Thomas Tschoepke Soares | // Mate do
> | RS - Brasil| [EMAIL PROTECTED] |(~~~//'~) estrivo
/Matti Aarnio
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