http://jkroon.blogs.uls.co.za/it/networking/3g-pins-prompts-and-pppd

This is due to the fact that they insist on using chat(8) for initializing the modem. On the SIM cards it’s actually an ERROR to send a PIN if the SIM is already unlocked, thus one actually needs to do a check, you need to query whether the modem is already unlocked or not (AT+CPIN? iirc), and then there is two possible responses, and based on that you either need to send the PIN (AT+CPIN=xxxx) or not before setting dialup parameters and dialing with ATDT.

So there you have it. A simple if statement in chat(8) would be extremely handy. Whilst possible to communicate with external files (or pipes … can you spell PIN prompts in X based on udev events?), combined with the REPORT option this can get the “daemon” to query for specific stuff, problem is still that we need to CONDITIONALLY prompt. This _MAY_ be possible using a little trickery using TIMEOUT.

No, something I’m more interested in is the ability to uniquely identify the SIM _before_ unlocking it. I can currently ID the modem (serial number etc …) but since there is no correlation between modem and sim this doesn’t help at all. Why? Well, simple, what happens if I have multiple modems and depending on which modem is in use I need different PINs, and I don’t want to be prompted the whole time (instead preferring to store a small text database with sim->pin mappings? No, I can’t use the modem as I actually swap SIMs between modems from time to time).

Now if only I actually liked 3G and used it more often I might be slightly more motivated to cook up something that works (triggered by udev … that part at least is easy, checking a config file for PINs, if required, and as a last resort, popping up a prompt – using Xdialog probably, rather ugly, but easily usable from a script – on the user’s desktop, and aborting if nobody is logged in).

Just a shame it probably won’t hook properly into network manager … at least, not directly.