modems with MNP

[Christopher Robin Thewalt]

I have a 2400 baud, MNP level 4 modem (IBC DATA24EC) connected
to the patch panel serial line on a VAXStation II running Ultrix 2.0. I
have an identical modem at home connected to a terminal. Now the claims are 
that an MNP 4 modem can actually get increased throughput, due to the 
stripping of stop bits and the like. So I have the modem to terminal and
modem to computer connections at 4800 baud with ^S/^Q flow control set.
The cables on both ends pass through all signals.

The result of all this is that with MNP on I see a 15% decrease in
throughput over a raw 2400 baud connection instead of the promised
increase. There is a noticable buffering delay every line or two, but I
don't know what I should do differently. Any ideas would be appreciated.

Chris
thewalt at cive.ri.cmu.edu
Carnegie Mellon University