Hello John!
03 Jun 95 14:32, John Maindonald wrote to All:
 JM> The message that comes up when the connection is made is
 JM>   CONNECT 57600/ZyX   16800/V42b/SREJ
 JM> (This is printed out by the script.)
 JM> What is the above message telling me?
 JM> Certainly I get a connection which is lightening fast relative to
 JM> my former 14800 bps connection.  Is the extra speed coming
 JM> largely from data compression?  Why is it even possible on a
 JM> modem whose maximum is supposed to be 16800bps, to start the
 JM> negotiation at 57600bps?
What your seeing with Connect 57600 is the locked baud of your serial port.
The 16800 portion is the actual connect rate between the two modems.
The SREJ is Zyxel's selective rejection feature that allows for only the bad 
portion of the data packet to be retransmitted instead of the whole packet.
The data is being sent to the modem at 57600 the modem then takes it and 
compresses if necessary before being transmitted at 16800.
The reason it is good to have the data sent to the modem faster than can 
actually be transmitted is that it provides the modem with as much data as it 
can handle.  Then if the data can be compressed it is compressed by the modem 
before being sent out.
A good example of this is to take a large text only file and transmit it.
At a 16800 connect you may actually have to boost the lock port speed to 
something higher than 57600 in order to maximize the transmission speed to 
its fully potential, this is because the average compression rate on a text 
only file is 4:1 or so the books and hayes say.  This is the case if you send 
a lot
of uncompressed files.  For most purposes your settings are just fine.
Thus 4 x 16800 = 67200 is what your port speed should be locked at but since 
this does not fit very well, you should 76800 which the next convenient 
multiple.  The next step for a port speed to be locked at is 115200.  This by 
the way is the maximum for most pc serial cards......  unless you get 
something like a hayes accellerator card which will shove the data to the 
modem at
230,400 bps.
Finally don't worry about your settings..... your settings are actually just 
fine.  I have my port locked at 57600 and I generally get between 2200 and 
2300 cps when I connect with another Zyxel E+  (19.2)
Live Long and Prosper,
Derek
--- GoldED/2 2.42.G0214
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