Short question:

How can I obtain detailed information about my SIM card, using Android apps and/or adb (possibly root)? I'd like to diagnose mobile data connection problems possibly caused by SIM card defects.

Extended context:

I just changed my mobile operator and got a new SIM card, and everything seems to work fine except that I cannot access Internet using mobile data: whenever I try to go to any site or use any app which requires network access, a "Login required" notification pops up. Activating it opens the browser in my mobile operator's homepage, and every other site is redirected to this one.

The thing is, I do have mobile data credit, but my provider seems to be blocking it. I suspected an issue on their side, but after explaining it to technical support, they dismissed it as "probably a faulty SIM card" and told me to get another one (free of charge).

However, I can still make calls (local calls are included in my plan) and access EDGE/3G antennas (they are detected, and I can access my provider's homepage via them). I do not understand how could a defective SIM card allow this kind of behavior.

I had Wifi disabled during my tests. The APN has been configured as defined in the SIM card and checked twice to match the one suggested in their website (resetting the APN or putting the SIM on another phone reverts to the prescribed settings). Indeed it's a captive portal, intended for when you run out of mobile data (so that you can top up using your mobile and credit card), but in my case I do have available data.

I would like to know if there are apps or some adb commands which could provide more details about what's actually happening.

Note: the issue is not Android-specific (e.g. an old Symbian Nokia phone exhibits the same behavior), but I hope that a (rooted and unlocked) Android phone can provide me more detailed information about this situation.

  • 2
    The connections you seem to get are running via a captive portal, most likely WiFi. Check the APN settings (of your mobile connection, not the WiFi ones), and ask the service staff to send you the related settings as service SMS (and optionally in readable format to either compare or setup manually). – Izzy Mar 11 '15 at 16:16
  • This is why I am almost sure it's a problem on their side, but I need stronger evidence to make their technical support understand it. – anol Mar 11 '15 at 16:28
  • Thanks for the update! Those facts are too important to the issue to leave them in a comment, hence I've integrated them with your question directly. I agree with your reasoning, but am afraid you won't convince them. Keep the proof, though, as when the new SIM shows the same issues you'll have something to show them then. I'd say if the SIM were faulty, it's unlikely you can connect to that captive portal but not to the regular AP – either it works or not. I'd rather bet it's on their end not accepting your account on the regular data line (missed to activate it there). – Izzy Mar 11 '15 at 16:32
  • Thanks for the edit. I did try to point that to them several times, but it must be simpler to just send another SIM ("follow the procedure"). Now, they are actually an MVNO and their own technical support needs to contact the actual provider's technical support, which complicates things. And also, even after making calls my "remaining local calls" counter does not move. In theory I could have unlimited local calls, or it's a glitch on the web interface. Anyway, having more information about the SIM card from my mobile phone would also be useful for curiosity's sake. – anol Mar 11 '15 at 16:43
  • 1
    In that case: Say nothing, get a second card for mobile data – unlimited calls is nice :) Good luck with it! – Izzy Mar 11 '15 at 16:45

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