I wonder if there's a reversed solution: using physical SIM card on devices that have only eSIMs. The use case: recent fewer versions of iPhone support only eSIMs, yet we will need a physical sim when traveling in China (yes yes, one could use roaming. It's just that with a China phone number, one can do more).
Using eSIMs with devices that only have a physical SIM slot via a 9eSIM SIM car
61–70 of 244 posts
Re: Using eSIMs with devices that only have a physical SIM slot via a 9eSIM SIM car
#62Does anyone have any resources which explain why eSIMs tunnel your network traffic to the provider? My mental model for old fashioned physical SIMs is that they would roam on the network you're visiting. ie, a Chinese physical SIM on a US network would show up from the US network, and would otherwise be normal except that the phone and network traffic would be very expensive. My understanding of eSIMs is that they act more like a VPN; your network (and phone?) traffic is tunneled back to the home network.
Re: Using eSIMs with devices that only have a physical SIM slot via a 9eSIM SIM car
#63Earlier quoted context omitted.
The service is called Holafly, it was advertised on the plane, and my travel mate bought it without hesitating (because of the convenience of an eSIM, even though they didn’t get a local number)
>it was advertised on the plane That's basically guaranteed to be overpriced. Anything prominently advertised means you're going to be paying for the advertising budget. Also, it's "unlimited data", which probably makes it more expensive than it needs to be due to adverse selection. For instance it charges $50 for 15 days in europe, but on esimdb[1] you can easily find esims for just over $1/gb. It might still be wor…
I found my google maps app for navigation and image translation via google lens/translator app ate up a ton of my data. I had to turn off off a setting or two to reduce the maps data.
Re: Using eSIMs with devices that only have a physical SIM slot via a 9eSIM SIM car
#64Does anyone have any resources which explain why eSIMs tunnel your network traffic to the provider? My mental model for old fashioned physical SIMs is that they would roam on the network you're visiting. ie, a Chinese physical SIM on a US network would show up from the US network, and would otherwise be normal except that the phone and network traffic would be very expensive. My understanding of eSIMs is that they ac…
> My mental model for old fashioned physical SIMs is that they would roam on the network you're visiting.
No, that's never really been the case. It's technically possible (and called "local breakout"), but for various reasons I also don't fully understand, it's usually not done that way.
One is legal liability for user actions; another is accessibility of services at home, such as banking apps, that are probably more comfortable with a familiar IP.
Re: Using eSIMs with devices that only have a physical SIM slot via a 9eSIM SIM car
#65I always wondered - can you have no roaming if you use eSIM with wifi calling and an exit node in country where eSIM is issued? So, basically: - you bought eSIM in Germany - you are currently in US - you use tailscale with exit node at your apartment in Germany - voila, no roaming when you call German mobile lines Right? [EDIT FOR ADDITIONAL QUESTION] If I have troubles receiving SMSs from Germany to German number wh…
Alternatively, use a global eSIM purely for data access, then use your phone as a SIP client (or use something like Google Voice) for PSTN access, eschewing the mobile network entirely.
Re: Using eSIMs with devices that only have a physical SIM slot via a 9eSIM SIM car
#66I wonder if there's a reversed solution: using physical SIM card on devices that have only eSIMs. The use case: recent fewer versions of iPhone support only eSIMs, yet we will need a physical sim when traveling in China (yes yes, one could use roaming. It's just that with a China phone number, one can do more).
It apparently can be done: https://www.youtube.com/watch?v=twFC0A_m0KI
Supposedly the people doing this at scale (for grey imports?) even de-solder the eSIM module and resell it, but I have my doubts about that part of the story.
Re: Using eSIMs with devices that only have a physical SIM slot via a 9eSIM SIM car
#67Earlier quoted context omitted.
What prevents you from doing that? Is an activated eSIM linked to the device's MAC address, making it impossible to use with a different device? If that is the case, what would happen if we transferred the MAC address along with the eSIM? (assuming you have a jailbroken/rooted phone)
>Is an activated eSIM linked to the device's MAC address, making it impossible to use with a different device? After an esim is "activated" it's bound to the esim chip. By design, you can't copy it onto another esim chip or device. If you want to transfer devices, you need to ask your carrier to issue you another esim.
What if you use a solution like the one described in the article, and physically swap the SIM card to another device?
Re: Using eSIMs with devices that only have a physical SIM slot via a 9eSIM SIM car
#68This is neat. I’ve only heard about ESTK [0] and sysmoEUICC by sysmocom [1]. ESTK supports a couple neat features, like cloud provisioning of profiles [2] (which makes it possible to add eSIM profiles on iPhone, too, not just Android). [0]: https://estk.me/ [1]: https://shop.sysmocom.de/sysmoEUICC1-eUICC-for-consumer-eSIM... [2]: https://docs.estk.me/manual/download/cloud-enhance/index.htm...
Note cloud provisioning does require an active data esim profile on the card already
Interesting, do you know why that is the case? Does it use BIP as a communication channel, and the iPhone doesn't route that over Wi-Fi?
Re: Using eSIMs with devices that only have a physical SIM slot via a 9eSIM SIM car
#69Earlier quoted context omitted.
Recently I tried to reinstall an eSIM on my Android phone while overseas but was told by my carrier that the eSIM can only be activated while connected to antennas located in the carrier's country, i.e. it can't be activated overseas, despite my plan supporting call roaming and both countries being in the EU. I don't know whether this is carrier-specific or the same for all carriers.
I think almost all carriers require this. I've seen mentions that the Google Fi eSIM requires US towers to activate, but can be moved / reinstalled later without them (didn't test it though).
Just an end user, so don't quote me on this, but I think that requirement was largely a legacy Sprint requirement.
I've purchased newer Pixel devices from my local shop and activated Google Fi just fine overseas. (with the caveat that I might not have all of T-Mobile's bands if I'm back in the US).
Re: Using eSIMs with devices that only have a physical SIM slot via a 9eSIM SIM car
#70I always wondered - can you have no roaming if you use eSIM with wifi calling and an exit node in country where eSIM is issued? So, basically: - you bought eSIM in Germany - you are currently in US - you use tailscale with exit node at your apartment in Germany - voila, no roaming when you call German mobile lines Right? [EDIT FOR ADDITIONAL QUESTION] If I have troubles receiving SMSs from Germany to German number wh…
Many providers actually let you use Wi-Fi calling without any VPN, i.e. they don't arbitrarily restrict the set of allowed IPs that can connect to their Internet gateway.
> If I have troubles receiving SMSs from Germany to German number while in US, would wifi calling icrease the chances of receiving the said SMSs?
Probably not, unless your provider supports inbound and outbound SMS via ISM. If you have an iPhone, you can check whether yours does in Settings -> About -> Tap the name of your carrier. (If it lists "Voice and SMS", you might be good; if it's only "voice" or nothing at all, SMS will go over the visited network.)