VoLTE provider support

Oh, wow. I’ve seen numerous broken/glitchy SIM card during the years, I didn’t think the age of the SIM card would matter (especially if they were only a few years old), but apparently there can be significant differences. This is an important piece in the puzzle, thank you for sharing it!

VoLTE indicator would indeed be nice. Could you make a separate post about it in the feature requests section?

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I’d also like to know! On vacation in France (02 Germany client) I actually ended up using prefer 3G in Southern France ( Occitania ), so I wasn’t even thinking about Volte.

I just want to leave a note to say that I have working VoLTE with Swedish provider Telavox.
Needed to edit service_provider_sim_configs.xml (the same as for Fello), both Fello and Telavox seem to be using Telia as their upstream carrier.
This is on a Xperia 10 II phone running SFOS

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This is great to hear, and thank you for sharing the info @sunkan. Would you mind please adding the info to the wiki (the very first thread)? If you can’t edit it, please say.

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Well for VoLTE FreeMobile have activate it… only Sony do not add support for Xperia 10 2&3…
Look like Xperia 1 IV is full supported…

May be we only nead de find the good config… but don’t know how…

Without reading the whole thread I want to add that VoLTE on O2 Germany and X10II registered and worked at the beginning but is not being able to register anymore. I have no clue when it stopped working, but rebooting and re-inserting the SIM didn’t help.
Any ideas?

edit: thigg solved it with a hard reset of the device and this also solved it for me. VoLTE works again.

I can confirm that voLTE has been working OK with T-Mobile in the USA (west coast) on my Xperia 10iii, for the last 24 hours. I just clicked the “4G calling (beta)” button in the Cellular network settings, and chose Network mode: “prefer 4G”, no Roaming. I even put the phone in Airplane mode overnight and the voLTE registration revived in the morning OK. My NetMon voLTE status looks fine, just like hackman238’s above. Just prior to this test I upgraded SFOS to version Voice and SMS work OK, but one problem: I cannot get MMS to either send or receive.
Access point: fast.t-mobile.com
Protocol: I’ve tried them all: Dual mode, IPv6, IPv4
I tried turning off Wifi (which used to help on my old XA2)
Authentication: None
Proxy: I’ve tried None, and also the one hackman238 suggested.
Message center address: http://mms.msg.eng.t-mobile.com/mms/wapenc
If anyone can help with this it would be much appreciated.


Currently in Australia from the UK. Have 2 sim cards in my X10 iii. In SIM 1 is my UK EE card on roaming, in SIM 2 is a local Australian sim from Telstra. Have travelled from Sydney to Perth across the country. Niether work for VoLTE, which is different to the Telstra entry at the top.

I thought it was said that the 10 iii wouldnt work in the u.s. because it didn’t have the right frequency bands?

The Xperia 10iii with voLTE works fine in Los Angeles for me now for 2 weeks on T-mobile, (and I once got it to work on Verizon briefly). But I recall reading somewhere in SFOS forums that the 10iii doesn’t support all the frequencies used in the US. So depending on where you live it might not work.


T-mobile has worked for me in NY & the New England states as well as North Carolina.

I just recently bought a 10 plus because it has all the frequencies. And i cant get it working because i cant seem to downgrade it to android 9. I would have preffered the 10 iii.

IIUC you don’t have to downgrade to Android 9, as long as you have the correct AOSP package. That was the case for my X10III, it should apply for other Sony models too. Could someone confirm?

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As of VoLTE now works for both in- and outgoing calls with O2 simcard.


Volte seems to work now in both directions on telefonica (eplus/o2).
However I had problems calling and being called, couldn’t reproduce this in tests however.

what isn’t working is sending sms when volte is enabled.


@flypig how should we update the table if the situation changed with .72?

A good question and thanks for asking.

I think it makes sense to keep the table up-to-date with the most recent release, so if something changes (either for better or worse) then it makes sense to edit the table to reflect this.

The calls (and mobile data) crash on my 10Ii now frequently when calling with volte. (telefonica/alditalk)

  1. Bluetooth headset connected, working fine
  2. I call
  3. No ringtone
  4. Message, telling me that recipient is not available starts playing via phone speaker for 1 second
  5. Call hangs up
  6. Mobile connection crashes, no network at all
  7. Reconnects

should i create a separate bug report? Can I collect helpful logs somehow?

After some fiddling (, got my Bulgarian provider Yettel running on VoLTE. A bit of a problem since it wasn’t listed in getprop. So, in order to find your VoLTE SIM config ID, check this XML:

As you can see, the providers are listed by their MCC/MNC and no names. To find a provider MCC/MNC, you can either check your CSD or NetMon tools on the phone, or check some provider listing, for instance this one in Wikipedia (first three numbers are MCC, the rest - MNC):

Since my provider was Telenor, before they sold it to Yettel, I just copied the Telenor Norway config (S260.1) to a new Yettel one (S232.1)

Country: BG
Provider: Yettel
Device model: 10 II
Registered: ✓
Voice in: ✓
Voice out: ✓
SMS in: ✓
SMS out: ✓

Have fun finding yours. :slight_smile: