SUMMARY: Need Gettytab Info for Hayes (Accura 144) Modem

From: Colleen Lagrotteria (lagrotte@dcseq.uscga.edu)
Date: Tue Sep 20 1994 - 23:11:07 CDT


Question:
>Is it possible to set up the Hayes Accura 144 modem on Sun 10/51 even
>though there is no 14400 baud in the /etc/gettytab? If so, would
>you please send me the copy of /etc/gettytab for using Hayes 144 modem?

Answer:

1) From: Kenneth.Erickson@Eng.Sun.COM (Ken Erickson)
   -------------------------------------------------
You should set up a 19200 bps entry for the modem. Be sure you have
the modem configured to do flow control, and lock the DTE-DCE speed
at 19200. Then you can use std.19200 for the gettytab entry.

Generally, this is the best way to install high speed modems.

Also, if you are planning to use tip or cu to dial out, be sure
you only connect to the modem at 19200 bps. This is crucial, since
most modems figure out which baudrate to lock onto based on the speed
of the last command sent to them.

2) From: celeste@xs.com (Celeste Stokely)
   --------------------------------------
You can't run a getty (or anything else) at 14400 on a Sun cpu serial port.
Your modem is probably able to run with a DTE rate (modem-to-Sun) of 19200
or even higher. Program your modem and the getty to run at the highest
baud rate you can reliably sustain (9600, 19200, or 38400). Further program
the modem to vary the DCE rate (modem-to-modem) as required by the connection.

3) From: szh@zcon.com (Syed Zaeem Hosain)
   --------------------------------------
Yes. It is *always* best to use rate independence. I.e., set the serial
port to the fastest value (remains fixed at that rate) that works well
for communication to the modem, and let the local modem run at whatever
rate it negotiates to the remote modem. These two values are generally
different.

In other words, what is likely to work best for you is to use the
serial port at 19200 or 38400 bps (the faster the better - to take
advantage of the compresion capabilities of the modem), and let the
modem change its rate depending on what is called or what calls it.

You do not need another copy of this file. Simply use the 38400 entry
in the file that you currently have.

If you want more specific details for SunOS 4.1.X, get my PostScript
"ftp.zyxel.com:/pub/other/zyx_sun.ps.Z". If you are running Solaris
2.X, get Celeste Stokeley's paper on the topic - archie for it.

4) From: Robert Sargent <sargent@wspan-cmd1.panama.army.mil>
   ---------------------------------------------------------
The 14400 is the telephone line speed. We run the port speed
fixed at 38400 on the accura 14400 with no problems at all.

Just add the :p8: parameter to the gettytab for std.38400
to correct the garbage that first appears on the screeen.

Thank you all,
It works with using 19200 entry in the /etc/ttytab file.

- Colleen Lagrotteria
  lagrotte@dcseq.uscga.edu



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