home
***
CD-ROM
|
disk
|
FTP
|
other
***
search
/
Cream of the Crop 3
/
Cream of the Crop 3.iso
/
comm
/
zoomhint.zip
/
1914
< prev
next >
Wrap
Text File
|
1994-01-03
|
3KB
|
47 lines
12-20-93 Phone Line Speed/BPS, DTE Speed
(applies to data only)
Most of the time, there is no need to use a bps above 19,200bps though
sometimes you may get an improvement is transfer speed when set at 38,400
(especially with the new 24K or 28K` modems). Unless the data is very
structured or has lots of empty space (database or spreadsheet) the
compression won't get you over 19,200bps (14,400 modem). When the modem
refuses to work above 19,200 or doesn't work well, it is usually hardware
on the computer (slow serial port or some other conflict even on a fast
computer). Set the software and dialing directory for 19200. Make sure
CTS/RTS flow is=ON. And locked DTE (baud/bps) rate (software does NOT
follow modem connect speed). The computer-modem speed you set, is not the
same as the modem-modem speed over the phone line. The modem will take care
of it's line speed when you set 19,200 or 39,400.
>>> The Windows com.drv will not handle over 19,200 reliably. A
replacement such as Turbocom will be OK.
On the other hand, never set the modem BELOW 19,200 either. If you get
a 12,000 or 14,400 connect the software and modem may not speak to each
other correctly.
(Applies to data & fax)
NOTE>>> The phone company claims the bandwidth of the phone lines will
only support 9600. Most of the time, from most locations we know from
experience that often 12,000 or 14,400 can actually be acheived. However
when the connections for whatever reason won't support the faster speed, it
should come as no surprise. Sometimes you can force a higher than 9600
connect, and get some (or a lot) of garbage characters. When the connect is
TOO poor, the modems will not even stay connected. In such a case use one
of the 9600 dial prefixes (insert or pp11-7 or 10-7) or set fax to a slower
speed. If you connect at a slower (9600) speed a file transfer may actually
be faster than at 14,400 because of a 'clearer' connection. The latest
chips normally will try to negotiate a speed slower than 14,400 or 12,00
if line conditions aren't good enough. So if you are forcing the higher
speed, you may never connect.
BTW: There are very few (if any) 14,400 Fax Machines out there. It is
unlikely you'll encounter 14,400 often, when using fax.
12-27-93 >>> NOTE: <<<
The problem of high-speed connects is likely to be worse, with the new
24K and 28K modems. I can test any number you are having trouble with.
Don Hinds - Zoom Tech
##include=c:\text\signa.tif