Physical SIM + VoIP + SilentLink eSIM in Europe Question.

xyzalphabeta

Gm everyone,

Since Europe has mandatory KYC with physical sim cards and I already own a sim card and I need access to that phone number (banking / family etc) I thought of the following solution.

I will leave my physical sim in my old phone (w cheapest contract) and setup call forwarding to a VoIP number on GOS. For my Data I want to install an eSIM through something like SilentLink. This way I can do most of my phone calls via Signal or Sandboxxed Whatsapp and receive the occasional actual phone call on my call forwarded VoIP.

A - does anyone have recommendations for VoIP services in Europe that work in this setup?

B - does this setup make sense?

In my thinking this setup allows me to still be a functioning member (receive calls, have mobile data etc) in society however I fragment any inherent telecom tracking since the physical SIM stays in one place.

Probably overkill but I like to tinker.

xxx

xyzalphabeta For my Data I want to install an eSIM through something like SilentLink.

Can recommend silent.link it works good.
I'm not aware of any VoIP services that don't need registration.

xyzalphabeta Probably overkill but I like to tinker.

Perhaps use the sim only when needed?

littlerack

What number will you use with public services, government, financial institutions (banks, brokers) or DHL/FedEx etc?
From what number will you place outbound calls?

xyzalphabeta

I guess my OG simcard in my OG phone (or GOS?), since its a KYC'd number and I'm not looking to go off-grid entirely. Its more about trying to fragment daily habit tracking etc. I guess I could carry the simcard with me (seperate from a phone) for outgoing calls (also in case of emergencies). I think what I'm trying to do is hack the cellular unavailability that comes with not having a simcard in your GOS phone.

littlerack

Probably9857

xyzalphabeta cellular unavailability that comes with not having a simcard in your GOS phone

I feel like I'm constantly repeating this, but here goes...

Not having a SIM is neither necessary nor sufficient to avoid cellular networks.

Airplane mode does that (with or without a SIM).

xyzalphabeta

Probably9857 sure, but in airplane mode you are unreachable by default, which is what I'm trying to hack. So that defeats the purpose.

xyzalphabeta

xxx yeah thats always an option sure :-) Its just that I was trying to see if I can set it up in a way where I am 'reachable' but not actively 'trackable'.

thmf

xyzalphabeta If your phone is not in airplane mode you are trackable. It doesn't matter if you have a sim or not.
If you'll find a VoIP provider that works for you chances are you could just move your old number from your KYC sim to them and drop the whole "old insecure phone + sim + monthly-money-hungry contract" setup.
This way you could enable airplane mode + WiFi + VPN and be reasonably not trackable or at least way less trackable. You could add silent link to that setup for on-the-go VoIP reachability via VPN, which is still trackable, but at least not via your KYC phone number.

xyzalphabeta

thmf sure but in airplane mode you do not have mobile data from the silent link esim either.

thmf

xyzalphabeta sure but in airplane mode you do not have mobile data from the silent link esim either.

Yes, but unfortunately when it comes to trackability we don't have much choice here. Cellular networks must track by design, it's how they work, they must know where you are to route a call to the base station you're connected to. So yes, it's either on-the-go, but very trackable, or WiFi, but with better privacy. +VPN in both cases.

xyzalphabeta Let me elaborate a bit on what @xxx means. Is your old phone a supported GrapheneOS phone? If not, then...

xxx You can also put the old sim in your Pixel and activate the sim only if needed.

...and most likely be safer from security stand point and probably less trackable from privacy stand point. And don't have the headache of having two devices.

xyzalphabeta

anyway I just use wifi or the data of silentlink (over VPN obv) and for now keep my sim in my old phone as I hardly need it. I keep that in airplane mode and charged.

xxx

xyzalphabeta

You can also put the old sim in your Pixel and activate the sim only if needed.

xxx

thmf most likely be safer from security stand point and probably less trackable from privacy stand point

I'm not quite sure about the tracking. But I find a sim that is with me (if needed) useful.

thmf

xxx What I mean is in a setup where you have 2 sims, one is data-only and the other is your regular phone number, you are:

Way less trackable if Airplane mode is on, since the cellular modem is off and your phone isn't automatically connected to any cellular base station. Add WiFi + a good reputable VPN here, disable WiFi calling, since it's not routed via user defined VPN tunnels. Now your concern is only the known default GrapheneOS connections. As some of them won't be routed via user defined VPN by design, for example some of the connectivity checks:

Connectivity checks are performed for each network connection and for VPN connections on top of those.

Way more trackable but still to an extent if data-only sim is active, since your cellular modem is active, but a noKYC sim + a reputable VPN takes care of a lot of data points.
There's also this myth circulating that if you're roaming, a cellular ISP you're currently connected to has way less data about you. I don't have any information from a reputable source on whether it's true or not or if it was true at some point, but not the case anymore. I'd appreciate if someone knowledgeable in the topic chime in and share where we are with this currently.
Greatly trackable if your regular sim is active, since its most likely a KYC sim. But with GrapheneOS you still have hardened security by design, thus privacy, thus less tracking data points.
So having your regular sim on GrapheneOS rather than on any other phone is better, than having a GrapheneOS phone + a separate non-GrapheneOS phone for a regular sim. Especially with the benefit of using the sim on-demand.

xxx

thmf Way less trackable if Airplane mode is on

Yes so true but if you turn on a sim or WiFi (or both) you are in some sense traceable.
Provider, WiFi operator, state ...

sappy_junior728

thmf

Why disable WiFi calling? Otherwise, won't you have to use the cellular network, which is even less secure and trackable? I want to spend as little time on the cellular network as possible.

I'm also curious if it's established that roaming with a foreign SIM is more private since you don't go through KYC on the roaming network. For example, if the U.S. government or ICE wants more information, my assumption is that they'll have to figure out who the foreign roaming carrier first and then seek information from that country and mobile carrier. That takes time, and the process inevitably creates friction for them. Foreign law will apply, not US law. Of course, this is all theoretical, and I'm not sure how things will actually work in practice.

xyzalphabeta

So you can switch off the sim, whilst it is inserted, effectively carrying it with you at all times, but never connecting to any cellular tower? So you have a disconnected sim, whilst not needing to be on airplane mode so you still have 'nonkyc internet' through the esim... Right?

In that case having the sim in your phone but switched off and having a non kyc esim for your data and porting everything to a reputable VPN seems like the most clear win-win scenario here.

I did read that sim cards identify your unique device number? Doesn't really matter in my case realistically, since I'm not running from anyone or trying to stay fully off grid. Just trying to learn stuff :-)

thmf

sappy_junior728 Why disable WiFi calling?

WiFi calling isn't routed via user's VPN, so the IP of WiFi router you currently use will be known to your cellular ISP. Hence to lower trackability WiFi calling may be disabled.

xyzalphabeta I did read that sim cards identify your unique device number?

Your phone has a unique IMSI number (like a serial number) and when airplane mode is off (cellular modem is on) your phone is automatically connected to a cell tower even if you don't have any sim cards installed.

with this connection you can for example call emergency services
your phone's IMSI is known to the cell tower, thus you phone is identifiable.

Sim cards just work as a login / password (phone number) for cellular network. You authorize in the network with it.

xxx

xyzalphabeta So you can switch off the sim, whilst it is inserted

Yes -> Sim1

xyzalphabeta internet' through the esim...

This must be another Sim. -> Sim2

xyzalphabeta n that case having the sim in your phone but switched off and having a non kyc esim for your data

Should work and reduce tracking. In case of emergency or if really needed you can use SIM1.

xyzalphabeta

thmf aha so then the questiom becomes, who do you allow to know that the device is linked to your identity.

Basically needing a physical sim is an imperfect setup and thus inherently comes with privacy flaws. No easy way around it. I guess this was why i thought of the call forwarding setup because this allows for cellular within linking the device.

Oggyo

thmf Your phone has a unique IMSI number (like a serial number) and when airplane mode is off (cellular modem is on) your phone is automatically connected to a cell tower even if you don't have any sim cards installed.
with this connection you can for example call emergency services
your phone's IMSI is known to the cell tower, thus you phone is identifiable.

Did you mean IMEI instead of IMSI in your example?

sappy_junior728

thmf

I'm reading that WiFi calling from a phone will occur outside of the VPN tunnel, but GL.iNet employees have said that WiFi calling through a connected GL.iNet router with a VPN on will ensure WiFi calls go through the VPN tunnel. You seem to contradict them.

thmf

xyzalphabeta aha so then the questiom becomes, who do you allow to know that the device is linked to your identity.

Yes, with a SIM card it's your cellular ISP. Without a SIM card, but with Airplane mode off it's cellular base station operator and it can be correlated with the store who sold the phone via IMEI (store cameras are the next step). Without a SIM card, but with Airplane mode on it's your current WiFi access point owner.
Choose your poison :)

xyzalphabeta Basically needing a physical sim is an imperfect setup and thus inherently comes with privacy flaws.

And eSIM also.

xyzalphabeta I guess this was why i thought of the call forwarding setup because this allows for cellular within linking the device.

Right, but moving your existing phone number from a SIM to a VoIP provider is even better. Your current mobile ISP (which should be doing call forwarding in your scenario) won't have your call logs, text messages, and metadata. Also, you can just drop current contract with them and stop paying for cellular since you don't need their services anymore.