A/UX: Implementing Dialback To a Remote Location

This article gives the basic steps for setting up an A/UX system with dial-back capability. That is, after following these steps, you can dial into an A/UX machine from a remote location and have the machine hang up the line and dial your remote modem. Many A/UX users want this capability for security reasons.

Note: Either 4.3 UUCP or HoneyDanber UUCP needs to be implemented to have this feature.


1) Using "cu", "kermit", or other means, "login" into the remote UNIX
  machine.

2) Execute a program or a shell script saying "dialback"; the "dialback"
  should perform the following tasks:

  * Logout your current terminal session

  * Hang up the phone line

  * Put the originating modem in the listen mode

  * Set the proper TTY bits mode to be used as a dial-out port

  * Wait a couple of seconds

  * Clear the phone line

  * Dial the phone number the user provided

  * Execute "/bin/login" to respawn a login session.

Update note: UUCP under A/UX 3.0 is HoneyDanber.  A/UX 3.0 adds F protocol to HoneyDanber, so you can communicate over X.25 networks.

An historical note: Regarding the use of "/bin/ct" under A/UX 1.0 (or for that matter 1.1), "ct(1)" is a holdover from System III, and possibly even Version 7 UNIX days.  Therefore, it only implements dialer code for a DEC DN-11 dialer.  The DN-11 was an early dialer for non-smart modems.  "ct(1)" only sends the telephone number digits, because that's all it expects. There should be support for today's smart modems (or, at least, the Hayes command set) in all of "uucp/cu/ct".  But in A/UX 1.0 and 1.1, that is not the case.  Apple needs to implement either the complete 4.3BSD UUCP, or HoneyDanBer UUCP/CU/CT to have that functionality.
Published Date: Feb 18, 2012