on Cisco 1841 I have the following configuration:
dialer string 7020191191
dialer caller 0257517627 callback
ppp authentication chap callin
When I generate traffic from local LAN to an external IP address in order to trigger ISDN call, PPP authentication is working well.
In a callback scenario (ISDN call received by 0257517627) the router tries to perform remote authentication even if the callback to 7020191191 is considered as call-out and PPP authentication doesn't work.
How can I fix this problem?