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Using CERN ACB on CERN Linux 7.2.1/7.3.1


Foreseen closure of the ACB service

During 2004, it is foreseen to close the ACB service

Please see additional information for the after-ACB era on the web site

Temporary measure from June 30th 2004

Toll-free 0800 numbers no longer available

Callback service no longer available

User pays the entire communication cost

This page contains recipes for configuring CERN ACB service on CERN Linux 7.2.1/7.3.1 using modem connection. Currently we do not have the recipe for ISDN not having access to it.


  • Read ACB documentation.
  • Make sure you are registered for the service
  • pppd with MS-CHAP (Microsoft Challenge Handshake Authentication Protocol) and CBCP (CallBack Control Protocol) support compiled in:
    Warning: Standard Red Hat Linux 7.X pppd does not support CBCP correctly
    If you are using this distribution you must update your pppd package to the CERN patched version: (sources:
    CERN Linux 7.2.1/7.3.1 versions already include this update.


This is the recommended solution: However it may not work in some areas as CallerID must be transffered with your call. If in doubt , please try it first.

Command line script
Edit /etc/ppp/chap-secrets. It should contain following lines:

# Secrets for authentication using CHAP for ACB V90
# client                        server                          secret                       IP addresses

Substitute your NICE login id and password for NICELOGIN and NICEPASSWORD respectively.
Next download script and save it as /usr/bin/ (Do not forget to make it executable - chmod +x /usr/bin/
You must edit the script and change user settings:


(see the script for the description)
To connect type (as root on your machine) /usr/bin/
To disconnect press Ctrl-C.

GUI tools



The only callback method we support is using the
Command line script
Use the description above (In dialin section): The same setup can be used (make sure to change phone number in script.
GUI tools (unsupported)


  • Are you registered ?
  • Enable detailed logging:
    Add debug option to pppd.
    Reconfigure your syslog to log everything:
    Edit /etc/syslog.conf: Put there a line:
*.* /var/log/messages

then restart it:

/sbin/service syslog restart

- Retry with logging enabled (prefferably using the command line script method, it's much easier to debug):
Watch /var/log/messages for any obvious problem.
- Still does not work ?
Open support call to Please include the debugging information obtained following the recipe above, we are unable to resolve any call not including it.