Re: How to save pin number and auto-connect on startup?

[Dan Williams <dcbw redhat com>]

On Mon, 2010-09-06 at 13:59 +0200, Achim Weber wrote:
> Hi Dan
> 
> >>> For which function needs NM the PIN before dialing a connection? As the PIN is
> >>> saved in the connection profile, it is not necessary to ask the PIN in advance.
> >>> So there must be something different for which the PIN is needed!?
> >>
> >> actually Dan needs to answer that, but generally speaking the PIN is
> >> needed to unlock the SIM card. And you need access to the SIM card to
> >> book yourself into the GSM/UMTS network. No SIM card, no access to the
> >> network.
> 
> can you please explain why the PIN is needed before dialling the connection.
> Which functionality needs the PIN?

Many things:

1) registration status
2) signal strength
3) access technology status
4) SMS
5) location-based services
6) IMEI/IMSI (often)

On most "consumer" modems that I have in my possession (see [1]; some
are more functional than others) you are unable to do much of anything
beyond AT+GCAP or ATI before entering the PIN.  All other commands
return ERROR.  Most consumer modems have a "limited" AT command parser
that is used until the SIM is unlocked, at which point the full AT
command parser is available.  Until the PIN is entered the modem is
effectively unusable.

Without entering the PIN before connecting, you have no indication if
the device has any signal, whether you're roaming, etc.  So most of the
time you *do* want to unlock the device long before actually dialing up
the connection, if only to make sure you're not roaming so you don't get
charged $$$ the second you connect.

What I think we'll end up doing here is probably some combination of
"best effort" (ie, if we can get the IMSI we use that to identify the
SIM), maybe fall back to IMEI or USB IDs, and finally just have a
"Always ask me later" checkbox in the initial PIN dialog that suppresses
the initial dialog based on USB IDs or such.

Dan

[1] http://live.gnome.org/NetworkManager/MobileBroadband