Dual SIMs - No internet during phone calls

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1

HW - miatoll community port, v5.0.0.67(Tampella)
SIM 1 - 4G VoLTE / non VoLTE mode.
SIM 2 - 2G, no data.
Internet Sharing On using SIM 1.

During calls using SIM 2, Internet do not work on any devices connected to SFOS.

Is this normal or do i need to tweak some setting.

Thanks,

2

If your device isn’t ready for VoLTE, it switches to 2G during calls. This interrupts internet connection for the device itself and connected devices by hotspot. This is normal behavior and not an error. Internet connection should come back automatically abt. 10-15 seconds after terminating the voice call.

3

Hardware does support dual sim VoLTE HD calls. Prior to flashing SFOS, VoLTE icon was there on the top when running on MiUI.

My understanding is the phone need not switch to 2G on Dual-SIM hardware.

4

Best way is imho to ask the man who made the port for your device, if VoLTE is yet implemented into the port and how normal behavior should be during a voice call.
VoLTE is a protocol and has to be implemented into software/OS, so 4G capable hardware is always hardware-compatible with VoLTE. Yes, as far as I know, in 5.0.0.67 it should be implemented.
What does the display say during voice calls? Does it change to 2G or 3G during calls and after the call back to 4G? Do you have some VoLTE settings options in Settings menu? Is your device port 64 bit or 32 bit software?
There were situations reported earlier, where some settings not matching the network providers parameters and so connection couldn’t be established.

What does this mean? You have to set VoLTE to ON if you want voice and hi-speed data in parallel.

I hope, someone here will answer, who understands more than I. Good luck!

5

Good point regarding whether VoLTE is implemented into the port, will ask them.

What does the display say during voice calls?

There are no special VoLTE indicator on top, only the 4G icon is there on top and in Setting->System->Mobile network-> SIM 1 → it says 4G Calling (VoLTE) registered.

Is your device port 64 bit or 32 bit software?

It is 64bit port.

SIM 1 - 4G VoLTE / non VoLTE mode.

I have tried with VoLTE enabled(Registred), and also without VoLTE.

If your device isn’t ready for VoLTE, it switches to 2G during calls. This interrupts internet connection for the device itself and connected devices by hotspot.

Is above statement is only applicable for that particular SIM ?. Any Data connection / Internet sharing using second SIM should not be affected. Is this correct ?.

6

If this display is present, then VoLTE is implemented in your port. No more need to ask the porter for this. So, it displays also ‘registered’?

Maybe the device isn’t able to use both SIMs at the same time. There are such devices existing.