Use the authentication method from the mobile-broadband-provider-info
database if it is specified and supported (we support CHAP and PAP).
Default to CHAP if the database does not specify a method (i.e.: the
previous behaviour).
Make the authentication method configurable, CHAP or PAP, defaulting to
CHAP (i.e.: previous behaviour).
Implementation details:
o If PAP is configured, we NAK the CHAP authentication protocol option
in LCP configuration requests and suggest PAP instead. This works
around the amusing requirement of 3GPP TS 29.061 that modems must
send a forced positive acknowledgement of the authentication method
tried (i.e.: the modem will successfully accept any CHAP handshake,
but if the network only supports PAP, the modem will hang up
when it tries and fails to activate the PDP context)
o The PAP Authenticate-Request is resent a hard-coded three times at
ten-second intervals. This may be a bit too persistent. Chances
are if it doesn't work the first time, it'll never work, but the
RFC insists that we MUST retry.
According to the standard "3GPP 27.007 v6.8.0" Appendix C.2.11,
when sending multiple DTMF characters, these must go in individual
+VTS commands for each tone. This adopts the AT modem approach.
Before: AT+VTS=1234\r
After: AT+VTS=1;+VTS=2;+VTS=3;+VTS=4\r
Seems the CCFC implementation on Telit firmware is not v.250 compliant:
ofonod[445]: Aux: > AT+CCFC=0,2\r
ofonod[445]: Aux: < \r\n\r\n+CCFC:0,7\r\n\r\nOK\r\n
In certain cases the #QSS notification is never sent, or sent too early.
Make sure that we enable #QSS notification only after the modem has been
set as powered. Also make sure that we explicitly query #QSS in case we
missed the earlier #QSS notification.
EF_PNN was not being read properly (see TS 24.008, section 10.5.3.5a,
for network names format), which affected the displayed PLMN name for
some MVNOs. Some modems already read the file and return the right
string: these do not show the problem.