home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
DP Tool Club 15
/
CD_ASCQ_15_070894.iso
/
vrac
/
zhint594.zip
/
SPEED
< prev
next >
Wrap
Text File
|
1994-05-12
|
2KB
|
32 lines
4-12-94
Data transfer =S=P=E=E=D w/v42bis
If you connect with v42bis and get transfers in the range shown below,
you are doing fine, and probably transferring Compressed files (Zip, LZH
etc) or Graphics (all of which v42bis cannot compress further). If you do
well over the cps shown below then you are getting compression. The amount
of compression depends on the type of file. Some (spreadsheets, database)
compress a lot, some very little (exe, com) and some in the middle (text).
a 2400 w/v42bis is 290-320cps
a 9600 w/v42bis is 11-12,000cps
a 14,400 w/v42bis is 15-17,000cps
a 24K w/v42bis is 26-27,000cps
a 28K w/v42bis is 32,000cps +/-
If the transfer seems slow, you can see your 'true' connect speed when
you make the call by putting S95=1 in your init string. Then when you
connect it will give the carrier speed, instead of the computer-modem
speed in the CONNECT statement. (be sure Autobaud=OFF). The higher speed
modems by default will fall back to lower connect speeds if the line
quality is poor.
The best transfer protocol is usually Zmodem. Then Ymodem (sometimes
listed as Xmodem-1K) or Ymodem-Batch. Xmodem or Kermit can be VERY slow. I
also suggest try using the 'next-higher' speed modem-computer than the
modem-modem supports. IE: 14,400 to 19,200(or 38,400), 28K to 38,400.
Setting 57,600 or higher sometimes actually is slower than 38,400.
Don Hinds - Zoom Tech
##include=c:\text\signa.tif