Framed Dial Requests

3If you enable PPP call-back negotiation on a port, DIGITAL strongly recommends that you also enable some sort of authentication (for example PAP or CHAP) on the port. Without authentication, any user who happens to discover the phone number for that port’s modem could potentially request a call-back and run up unlimited phone charges.

4To enable authentication on a port, use the SET/DEFINE/CHANGE PORT LCP AUTHENTICATION PAP/CHAP command.

5If the PPP client specified a phone number to which the return call is to be placed, this phone number is also included in the dial request along with the name of the dialer service. If the PPP client did not specify a phone number, the phone number to be used is determined by the dialer service or the user’s authorization information.

6If a service name is specified that does not match an existing dialer service, the call-back will fail and an accounting event will be generated.

7Whether the phone number to be dialed comes from the PPP client or the dialer service definition, the user making the request must be authorized to dial that number. Likewise, the user must be allowed to create sessions of the mode defined by the dialer service, either interactive or framed. If the user is not authorized to either dial the selected phone number or create sessions of the mode specified by the dialer service, the call-back fails and an accounting event is generated.

8Unlike interactive dial requests, which require the user to log off the server and hang up the client’s modem in anticipation of a return call from the server, successful PPP call-back negotiation results in the initial PPP session being automatically disconnected. This also breaks the modem’s connection and results in the PPP client hanging up the phone, making it available for the return call from the server.

Managing Dial Services 21-17