I am trying to configure the APN with PAP authentication. According to the datasheet UBX-17003787 - R11 the following command should work:
AT+CGDCONT=1,"IP","PAP:APN.M2M" > +CME ERROR: 4 (Operation not supported)
However, the command gets rejected and if I use the command without "PAP", it does work:
AT+CGDCONT=1,"IP","APN.M2M" > OK
Unfortunately, this does not tell the modem which authentication protocol is used and during the LCP phase the modem will suggest CHAP first.
I could tell the modem to use auth_type PAP with the AT+UAUTHREQ command. However, this does not seem to accept empty username and passwords:
AT+UAUTHREQ=1,1 > ERROR
AT+UAUTHREQ=1,1,"","" > ERROR
AT+UAUTHREQ=1,1,"\0","\0" > ERROR
AT+UAUTHREQ=1,1,, > ERROR
AT+UAUTHREQ=1,1,"USER","PASS" > OK
Even when defining no authentication with AT+UAUTHREQ=1,0, the modem will suggest CHAP during the LCP phase.
Using AT+UPSD=0,1 would be a solution, however not supported by the modem.
SARA-R412M-02B with modem revision M0.07.00 [Sep 06 2018 18:05:31]
So is there another way to configure PAP authentication using AT commands and empty username and password?