km@emory.UUCP (Ken Mandelberg) (03/18/85)
I have been looking at some glossy literature for Microcom
modems, including their 2400 baud entries. The modems use
MNP (Microcom Networking Protocol) to allow error free
data transmission.
Here are some questions:
1) Does anyone know what the MNP algorithm is. I am really
only interested in the asynch case?
2) Does it work well under varying situations (no data - just
line noise, intermittent single character i/o, long bursts of
data). I would be worried that in the single character case,
the packaging might really cut down responsiveness. Remember
the raw data rate is only 300/1200/2400 on these modems.
3) Whatever the algorithm, there just has to be some overhead
even when there is no noise (and more when there is). The glossy
doesn't mention it, but I wonder if it the modem expects to
do flow control with the host and computer, and if so what
kind (XON/XOFF?)?. It strikes me that this could play havoc with
applications which use raw mode. The glossy has no mention
of a buffer in the modem.
4) The glossy says that MNP is rapidly becoming any industry
standard. (This is a little funny. Microcom has an advertisement
which shows a huge pile of their competitors modems, none of
which use MNP). Does anyone know what other modems use MNP, and
if there are other industry standards?
--
Ken Mandelberg
Emory University
Dept of Math and CS
Atlanta, Ga 30322
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