Original post: https://lemmy.sdf.org/post/34817172

Previous post summary: I wanted to activate foreign (Czech) eSIM, it didn’t work, so I traveled to Czech Republic (neighboring country), it didn’t work there either

So now I just tried it again (in home country). I just got the idea that, perhaps, I can try different LPA software. Can’t lose anything. I downloaded the profile, enabled it, AND IT FUCKING WORKS.

But OK, I tried the previous software with the second SIM. It… worked too?

To be fair, I still had the alternative installed, so maybe it did something in the background. (Like in terms of profile download notification.) I am not going to try a 3rd SIM.

The software

So, at first I tried EasyEUICC (https://gitea.angry.im/PeterCxy/OpenEUICC), or rather the rebranded JMP variant since that’s the same thing but also available on F-Droid.

Now I tried NekokoLPA (https://github.com/iebb/NekokoLPA) and that worked, but so did EasyEUICC so no idea if it is related.

I originally chose EasyEUICC because I like the UI more, and also Nekoko says “super unstable, use at your own risk”

AAAAaaah…

  • u/lukmly013 💾 (lemmy.sdf.org)@lemmy.sdf.orgOPEnglish
    3·
    1 month ago

    First of all, sorry, I know very little, and I am having trouble finding info.

    I thought eSIM relied on a dedicated chip to function, right?

    Yup.

    This is not magically enabling eSIM on an arbitrary phone?

    Well, not magically, but also it is. Just with the eUICC in form of a standard SIM card in SIM slot rather than soldered on.

    This is to manage eSIMs without OEM software?

    I mean, I guess OpenEUICC can also be used for internal eUICC. In this case there is no OEM software, since the phone doesn’t have eSIM functionality built-in.

    Alright, so to the specific case. I got external eSIM from 9esim. This includes ARA-M hash for EasyEUICC which unlike OpenEUICC works without having to root my phone. Although this also comes at a premium price.

    If I understand it right, the eSIM adapter just whitelists EasyEUICC app to allow managing it. Here’s some explanation of ARA-M I found: https://github.com/seek-for-android/pool/wiki/AccessControlIntroduction

    Now, another thing this specific card has is SIM Toolkit Menu for switching profiles. That’s the thing where in the past you could perhaps get news, weather, horoscopes, order ringtones, check your balance, etc. Since this basically works in every device, it means that it can be used there easily as well.

    Alternatively, with root you could likely just use any eUICC chip implementating the SGP.22 standard soldered to regular SIM contacts like shown here: https://xdaforums.com/t/a-tricky-way-to-use-esim-on-cn-in-variant.4609543/

    Pretty cool.

    Here’s a review of similar commercial offering (JMP): https://www.androidauthority.com/esim-adapter-android-phone-3480601/
    It also just uses rebranded EasyEUICC, but at least they got it on F-Droid as I mentioned.

    Risks (severe bugs)

    From Osmocom website, Pixel 4a 5G stops working with any external eUICC when you try to use the built-in manager. This issue persists.
    From various posts and reviews, Samsung’s SIM slots may get bricked. Users report missing IMEI, and the SIM slot not working with regular SIMs either afterwards. Yikes. Apparently, factory reset can fix this.