Am 2008-05-15 09:08:45, schrieb Michael Adams: > 56kb = 56000 bits per second. As serial data it is not 1024 bits per k
This is not right since my US Robotics Courier I-Modem is a 56k
ISDN-Modem and has definitivly 57600 BpS. The same is vor my
USR 56k Voice Modem. It HAS 57600 BpS.
> but 1000. It is also a maximum theoretical limit never usually attained
> in real world situations. Using 50kb in an urban environment is often
> much nearer the real world truth, distance from the exchange and line
> interference tend to be the two most common losses. Note that expecially
> in windows reported connection speed is the speed that was originally
> connected at and it can drop over time. Very few modems negotiate higher
> speeds again if line noise clears. For a long download you could then
> guess at around 45kb average for a 56k modem in an urban environment,
> much worse in a rural area.
I get even in teh Turkey in a distance of more then 50km rates arround
45 kBps not only in the cities...
> Hardware compression works at the packet level whereas zip works at the
> file level so V90 compression may still have a useful impact (not my
> field of knowledge, so i cannot say how much).
Not realy, since if the modem TRY to compress it lost time...
...and then it is slower.
> > Idealy, with compression, a 56kBit V.90 Modem can transfer up
> > to 35 MByte per second and an 64 kBit ISDN line up to 50 MByte per
> > second.
>
> WTF? per second? If you are sending a file that contains 10^9 identical
:-) per hour!
> bytes precompressed into a 5k zip file perhaps otherwise this statement
> is a bit misleading.
No, a sparse file:
dd if=/dev/zero seek=1G bs=1 count=1 |dev/ttyS0
Thanks, Greetings and nice Day
Michelle Konzack
Systemadministrator
24V Electronic Engineer
Tamay Dogan Network
Debian GNU/Linux Consultant
--
Linux-User #280138 with the Linux Counter, http://counter.li.org/
##################### Debian GNU/Linux Consultant #####################
Michelle Konzack Apt. 917 ICQ #328449886
+49/177/9351947 50, rue de Soultz MSN LinuxMichi
+33/6/61925193 67100 Strasbourg/France IRC #Debian (irc.icq.com)
signature.pgp
Description: Digital signature
