ITEM: H0472L

High Speed Modem does not stay connected at high speeds

Question:

AIX 3.2.2

I have a HS modem connect to my RISC.  At lower speeds, it works ok,
but I would like the modem to connect at 14.4K baud.  I have set the
DTE speed to 19.2K.  The modem does connect, but immediately drops and
I never get a login.  What is wrong?

Response:

   The symptoms are still there. When you dial in from the outside,
you get a Connect 9600, and garbage. You want to connect at higher
speeds, but seem unable to. Your setup is as follows:

    RS/6000 -- HSM -- /\\/\\ --- HSM ---- PC

    HSM - High Speed Modem

  You have a HSM connected to your RS/6000. On your PC side, you
have another HSM. We need to add the following lines into your 
Devices file, which is under /usr/lib/uucp :

     Direct tty10 - Any direct
     Direct tty10 - 19200 direct
     Direct tty10 - 9600 direct
     ACU tty10 - Any
     ACU tty10 - 19200 hayes
     ACU tty10 - 9600 hayes

When we try to dial in at 19200, it connects, with no problems. Now,
when we try to connect at lower speeds, we are not able to connect
properly.

 You will have to change your entries in smit to reflect that of the
Devices file.

  BAUD rate                                          [19200,9600>] +
  PARITY                                             [none,none..] +
  BITS per character                                 [8,8..] +
  Number of STOP BITS                                [1,1..] +

 Make the changes above to your smit configuration for that tty. Now,
when you try to login into the RS/6000, you are able to get a login 
prompt, but you also get a

   arq
   Login:
   arq's Password:

This seems to be something with the modem that is sending or not
sending, the right information. 

  The arq problem is part of the HSM sendings this to the RS/6000 as
part of the return codes. You have fixed this by surpressing the
sending of the return codes to the RS/6000. Also, we are able to
connect into the modem, but to the Devices file , under /usr/lib/uucp ,
we have added all the possible baud rate entries, this is for both the
ACU and Direct entries.

  When dialing in at 19200 baud, the connection is quick. But when
dialing in at slower speeds, i.e. 9600,4800,2400, garbage is sent out
before a login prompt appears on the screen. We have tried running at
1200 bps , but the modems do not connect properly and are
disconnected.

  AIX versions of 3.2.3e or lower do not have a very good capability of
accepting modems as ttys. As of AIX 3.2.4, modems have been adjusted
to be part of the tty subsystem and do properly work.

   You are trying to dial out of the system using the cu command. Now,
to be able to dial in and dial out from the RS/6000, you must set the
port as a shared port. Through smit this can be done, but at the 
command prompt, you can issue the following:

   pshare tty10

  Now, using the cu -d\ works properly.



Support Line: High Speed Modem does not stay connected at high speeds ITEM: H0472L

Dated: March 1994 Category: N/A

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