[Guide] Enable AT&T US HD Voice/VoLTE on non-supported W10M phones

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gchq

Member
Mar 31, 2022
13
1
It does say that, but, doesn't work. I tried it and it bricks the cellular modem and I had to reload a rom from PC to get it back. The modem files for dual sim are completely different than for single sim, there is probably a way to unpack the cab's in there and merge the single sim ones into the dual sim format but it's much easier to just get a single sim device. The dual sim stuff just really complicates things.
I've no idea on your Android question, never touched the stuff. To me using Android or iOS would be the same as using coke without a good high part.
I have say that I agree about iCrap and Android - the Essential I got just to upload cheques to Wells Fargo when they dropped support for the Windows phone with their app.

At the moment voice calls go to VoiceMail and as Visual Voicemail is data driven it still works and I can call them back from another phone. The lack of spam calls has been quite refreshing. :)

I'll look into getting a single SIM XL.

Edit

Looking around for a single sim XL I keep stumbling over forums where the poster was kicking off that the dual SIM doesn't work with Visual Voicemail. Interesting, mine worked with that from the get-go. I seem to remember that if someone booted up a new phone without a SIM inserted that was an issue, and problems with 4G.
 
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73blazer

Member
Feb 16, 2022
17
4
I'll look into getting a single SIM XL.

The single-sim RM1085 seems to be more prevalent in Europe. Do not buy the ebay "from china" ones, most of those are knockoffs and not real. I bought two brand new in box never used ones one from Jordan and one from the UK. There's lots of used ones out there too and the good part about a 950xl is if the screen is good, nothing else really goes bad except the battery which is thankfully easily replaceable.
 

gchq

Member
Mar 31, 2022
13
1
I have say that I agree about iCrap and Android - the Essential I got just to upload cheques to Wells Fargo when they dropped support for the Windows phone with their app.

At the moment voice calls go to VoiceMail and as Visual Voicemail is data driven it still works and I can call them back from another phone. The lack of spam calls has been quite refreshing. :)

I'll look into getting a single SIM XL.

Edit

Looking around for a single sim XL I keep stumbling over forums where the poster was kicking off that the dual SIM doesn't work with Visual Voicemail. Interesting, mine worked with that from the get-go. I seem to remember that if someone booted up a new phone without a SIM inserted that was an issue, and problems with 4G.
Interestingly if I go to https://sim-usa.mobi/phone-compatibility-check/ the existing IMEI shows as Incompatible with AT&T but 100% compatible with T-Mobile - the 950 IMEI is the exact opposite, 100% with AT&T and incompatible to T-Mobile
It does say that, but, doesn't work. I tried it and it bricks the cellular modem and I had to reload a rom from PC to get it back. The modem files for dual sim are completely different than for single sim, there is probably a way to unpack the cab's in there and merge the single sim ones into the dual sim format but it's much easier to just get a single sim device. The dual sim stuff just really complicates things.
The only reason a single sim 950 works is because AT&T sold it in their store and had the right rom to work on their network with the VoLTE/HD Voice stuff. So...that is where the modem files came from and can be used on any phone with the same modem (x50 devices in theory).... I tried on a X3 and that phone is laid out all different, the modem files aren't even in the same directory. The modem is different so they likely wouldn't work anyway..etc..etc..
I've no idea on your Android question, never touched the stuff. To me using Android or iOS would be the same as using coke.
Interestingly if I go to https://sim-usa.mobi/phone-compatibility-check/ the existing XL IMEI shows as Incompatible with AT&T but 100% compatible with T-Mobile - the 950 IMEI is the exact opposite, 100% with AT&T and incompatible to T-Mobile.

imei.net check confirms that the 950 IMEI is RM-1105 which I believe IS the AT&T model
 

73blazer

Member
Feb 16, 2022
17
4
They may at some point turn off the whitelist for VoLTE/HD Voice (or Enhanced 4g Services as they programmed into the Lumia 950) and just enable VoLTE on every device on the network as it's required anyway for voice and sms.... . That would negate the having to register a 950 IMEI with them for your hacked XL to work.
Keeping whitelists can be a pita for them.
One day when I have time to waste I might try registering an iPhone IMEI and see if I can get WiFi-Calling to turn on on my 950XL, I enabled all the registry for it and added the code, and I see it in my sim settings, but it does not work, I have a feeling it needs to be "enabled" with AT&T on their end. But I'm not sure if a different platforms IMEI will break everything or not.
 

gchq

Member
Mar 31, 2022
13
1
They may at some point turn off the whitelist for VoLTE/HD Voice (or Enhanced 4g Services as they programmed into the Lumia 950) and just enable VoLTE on every device on the network as it's required anyway for voice and sms.... . That would negate the having to register a 950 IMEI with them for your hacked XL to work.
Keeping whitelists can be a pita for them.
One day when I have time to waste I might try registering an iPhone IMEI and see if I can get WiFi-Calling to turn on, I enabled all the registry for it and added the code, and I see it in my sim settings, but it does not work, I have a feeling it needs to be "enabled" with AT&T on their end. But I'm not sure if a different platforms IMEI will break everything or not.
One can hope :)
Incidentally, what settings do you have on your working XL for APN and MMS APN?

Apparently iCrap is a totally different ecosystem to Android and Windows. Why MS bailed them out is beyond me, but there it is and now we have it!
 

73blazer

Member
Feb 16, 2022
17
4
Internet APN is "nxtgenphone" which is what you get when copy the new modem files from the 950 and VoLTE is activated.
There is no MMS APN, I believe that was a 2g setting no longer used. MMS had been routed via your data connection for at least a decade

wp_ss_20220411_0001.png
 

73blazer

Member
Feb 16, 2022
17
4
If I view the APN it's just all dehighlighted, I can't change anything in it. The APN is filled out as nxtgenphone (lower case) but dehighlighted. I never changed anything related to these APN, they should get filled by the carrier once connected to their network. I think for 3g the apn listed a URL IIRC. But once I did the VoLTE, it changed to nxtgenphone and blocks you out from changing it. The AT&T Branded 950 also shows the same stuff I got here on my hacked XL when I had the sim in it.
wp_ss_20220411_0002.png
 

nate0

Senior Member
Mar 27, 2015
965
158
I purchased a 950XL Single Sim version and it worked right away with the Puretalk SIM.

The only downside is that the version of windows 10 on the phone is very old and the windows update feature of the phone doesn't work. The store doesn't even work.

I thought that if I log in after a phone reset it would pull everything over?

I have a dual sim using the same windows account I was hoping to move everything over.

1. Is there a way to upgrade to the latest version of Windows 10 mobile
2. Is there a way to transfer all the apps from the dual sim to the single sim?

Thanks!
Have you tried the otc updater?
 

gchq

Member
Mar 31, 2022
13
1
As an interesting update - 950XL Dual SIM now playing with AT&T without changing any config files.

1. Get an old AT&T branded 950 and ask AT&T to change the EMEI to that one

2. Head into settings > Cellular & SIM > SIM 1 Settings and click to add an Internet APN



Profile name = For unlocked non AT&T Devices 2 (I think this is just free text)

APN = nxtgenphone (case it would appear is important - uppercase doesn't work)

IP Type = IPv4

Check 'Use this APN for LTE and replace one from my mobile operator'

Save



The 950XL dual SIM now works with VoLTE and all other 4G features :)

The SIM 1 reading now shows AT&T 4G instead of AT&T LTE as before.

=================== Edit =======================

As Alice would say, curiouser and curiouser.

After a while it resets itself back to LTE and once again voice calls fail.

If I go back into Internet APN, misspell the APN and save, it drops the connection - I can then re-edit it to the correct name and once again it connects as 4G and everything works for a while

I have noticed that the SIM name changes from 'SIM 1' to 'ity=Impersonation Dynamic False' whilst it is working.

Confused? You won't be after the next episode of SOAP!

SIM1_4G.png


SIM1_Imp.png
 
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nate0

Senior Member
Mar 27, 2015
965
158
As an interesting update - 950XL Dual SIM now playing with AT&T without changing any config files.

1. Get an old AT&T branded 950 and ask AT&T to change the EMEI to that one

2. Head into settings > Cellular & SIM > SIM 1 Settings and click to add an Internet APN



Profile name = For unlocked non AT&T Devices 2 (I think this is just free text)

APN = nxtgenphone (case it would appear is important - uppercase doesn't work)

IP Type = IPv4

Check 'Use this APN for LTE and replace one from my mobile operator'

Save



The 950XL dual SIM now works with VoLTE and all other 4G features :)

The SIM 1 reading now shows AT&T 4G instead of AT&T LTE as before.

=================== Edit =======================

As Alice would say, curiouser and curiouser.

After a while it resets itself back to LTE and once again voice calls fail.

If I go back into Internet APN, misspell the APN and save, it drops the connection - I can then re-edit it to the correct name and once again it connects as 4G and everything works for a while

I have noticed that the SIM name changes from 'SIM 1' to 'ity=Impersonation Dynamic False' whilst it is working.

Confused? You won't be after the next episode of SOAP!

View attachment 5597559

View attachment 5597561
Yeah I used to do this with the IDOL 4s and 950 XL on T-Mobile all the time. The idol 4s ADC files allowed cool features to be unlocked for T-mobile on the 950xl but wifi calling only worked on 2.4Ghz. The volte was always solid. However at times there was inconclusive or incomplete sim lock/provisioning and the GUI burped with that sim_name since it obviously was waiting for the variable to populate.
 
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gchq

Member
Mar 31, 2022
13
1
Yeah I used to do this with the IDOL 4s and 950 XL on T-Mobile all the time. The idol 4s ADC files allowed cool features to be unlocked for T-mobile on the 950xl but wifi calling only worked on 2.4Ghz. The volte was always solid. However at times there was inconclusive or incomplete sim lock/provisioning and the GUI burped with that sim_name since it obviously was waiting for the variable to populate.
Is there a way to get it to stick with 4G instead of reverting back to LTE?
 

nate0

Senior Member
Mar 27, 2015
965
158
Yes, I did it said no new updates. I assume the OTC works the way it used to where I don't need any local update files?

Thanks!
Yes, it downloads the cabs locally then pushes them to the phone. Make sure you are using the version of otc updater found here on xda because the one provided by Microsoft fails due to the version of authentication it uses. I personally would reflash the original ffu and update all from the otc updater from scratch. Could be something broke in Windows Mobile. What version did it end up on?
 

maximum56

New member
Mar 24, 2022
4
0
Good to know concerning the OTC, I have one from MS. Will track it down here. Do you have a location for the CABs? I assume the instructions for the FFU are somewhere on here?

I factory reset the phone and it never was able to download updates in the normal manner so it is stuck on a real old windows 10. I did some snooping on the phone and in the about it says this phone is a prototype and don't resell it, lol. We shall see if that is an issue. I noticed with you reboot the phone it has tiny text in the corner that my other 750's don't have. WP has the kids corner and the store is very old and it won't connect.

Thanks so much for the help!
 

nate0

Senior Member
Mar 27, 2015
965
158
Good to know concerning the OTC, I have one from MS. Will track it down here. Do you have a location for the CABs? I assume the instructions for the FFU are somewhere on here?

I factory reset the phone and it never was able to download updates in the normal manner so it is stuck on a real old windows 10. I did some snooping on the phone and in the about it says this phone is a prototype and don't resell it, lol. We shall see if that is an issue. I noticed with you reboot the phone it has tiny text in the corner that my other 750's don't have. WP has the kids corner and the store is very old and it won't connect.

Thanks so much for the help!
Do not update it. If it is proto then it might be running a special version of FW and W10M. You CAN update it you just will lose any Proto features or anything else related to that special FW. Also if it is a Lumia 750 then there will be no updates on the standard production branch since the 750 was for internal use and utilized developer internal branches for deployment.
 

z_row

Member
Aug 27, 2014
7
0
I have a Dual Sim 950XL that I booted back up after gchq mentioned he was having success. I find I have to alternate APNs once or twice a day to reset the SIM provisioning. Hoping this will go away as I really don't know if it is not connected until an outgoing call is immediately dropped (incoming calls will go straight to VM). I am using Red Pocket NVMO as my ATT carrier. Visual Voicemail has not worked since the 3g shutdown in my area (early Feb of this year)
 

Old_Mil

Member
Aug 30, 2018
18
7
Just curious if anyone currently has a 950XL in the United States that is functioning with VoLTE on T-mobile or ATT after the 3g shutdown.

I'm currently using a 640 LTE RM 1073 with T-mobile Windows 8 that drops back to 4g or 2g for voice calls and maintains an LTE connection otherwise.
 

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  • 5
    This is how I enabled AT&T US HD Voice/VoLTE on the Lumia 950 XL Dual sim and the factory Unlocked Alcatel IDOL 4s. It should work on the Lumia 950 Dual sim too, but I have not tested this method on it yet.

    *Requires full file system access with MTP or SFTP using Interop tools
    *All the files attached were taken from the latest AT&T Lumia 950 FFU (01078.00053.16236.35035 - OS 10.0.10586.318)
    *To reset everything back to original factory settings requires either a re-flash or you can take the files you backed up before hand and replace them back.
    **The one caveat to this is you need to use an AT&T Lumia 950 imei to register to your ICCID (sim card ID) with AT&T customer support to enable the hd voice/ims registration to come online. It might work with a Lumia 830 imei for AT&T too.
    ***There was mention of AT&T possibly whitelisting your device. This would allow IMS provisioning to complete without the need to have AT&T update your IMEI with that of a AT&T branded one. Seems even though you can ask AT&T to do this, it has not actually been proven to work. The only for sure way is to use a AT& branded Lumia 950 IMEI.

    Update 7/20/2017: Updated files attached to include the specific ATT-US files from the 950 XL rom RM-1085_15919 (product: 059X7S5). The modem file is slightly different as it provisions with the same bands that come default already on the 950XL, it will not remove band 17 like the 950 ATT modemconfiguration.cab file does. The modem files as far as I know only work on the x50 Lumia models and not OEM models.

    Install Interop Tools
    - Here is the link. I used version InteropTools_1.9.437.0_arm_RC3.

    Install Swish
    - This sftp client found here (needed for Lumia 950/XL) for explorer sftp support. For the IDOL 4s enable Full file system access via MTP with read write access in Interop Tools under the Unlock options/settings.

    Gain access to the file systems using Interop Tools app.
    - In Interop Tools go the SSH--Account Manager and add an account. The account user name should be System.

    - Tap the account System so it is highlighted and then tap templates to use.

    - Tap enable full file system access with sftp. Then go to the template options and hit the authentication drop down setting it to password.

    - Add the password (4 digit pin of your choice).

    - Once your phone is on wifi, add an SFTP Connection under Swish. Set the user to system. Set the path to /c/. Once added double click it and login with the pin you set. Explorer will open with your phones files. There is a guide in more detail on sftp file system access made by snickler if you need to see more details about this method.


    For the Lumia 950/XL do the below:
    - Copy and back up all files under C:\Programs\CommonFiles\ADC\Microsoft and C:\Programs\CommonFiles\ADC\OEM.

    - Then Copy and replace the files under C:\Programs\CommonFiles\ADC\Microsoft and C:\Programs\CommonFiles\ADC\OEM with the files of the zip file titled ADC.zip

    - Copy and backup the file under C:\Programs\CommonFiles\OEM\Public\MMO\Multivariant.

    - Then Copy and replace the file under C:\Programs\CommonFiles\OEM\Public\MMO\Multivariant with the contents of the zip file titled modemconfiguration.zip

    - From there do a hard reset.


    For the Alcatel IDOL 4s do the below using full file system access with MTP:
    - Copy and backup all the files under C:\Programs\CommonFiles\ADC\Microsoft and C:\Programs\CommonFiles\ADC\OEM.

    - Then Copy and replace the files under C:\Programs\CommonFiles\ADC\Microsoft and C:\Programs\CommonFiles\ADC\OEM with the contents of the zip file titled ADC.zip

    - From there do a hard reset.


    When the OOBE setup returns after hard reset, you may have a light blue/cyan theme and the display/dpi/font size may be a bit different too. This is due to the packages used from the AT&T 950. Go through the normal setup and let it fully boot to the start screen. Wait for the prompt to tell you to reboot your phone for settings/sim card settings to change/update.

    Alternatively you can add the two files in the zip file titled MO_VoLTE_1117.zip to the c:\windows\system32. This will replace the MO_VoLTE_Label_1117.dll and MO_VoLTE_Description_1117.dll details found near the volte toggle under Sim settings with the proper descriptions.

    To reset everything back to original factory settings requires either a re-flash or you can take the files you backed up prior and replace them back.

    Thanks to the creator of interop tools @gus33000. Without access to that tool/app this and other things like this would not be possible. To @snickler for finding and explaining the sftp file system access in a guide to help others like me use that method.
    1
    This is how I enabled AT&T US HD Voice/VoLTE on the Lumia 950 XL Dual sim and the factory Unlocked Alcatel IDOL 4s. It should work on the Lumia 950 Dual sim too, but I have not tested this method on it yet.

    *Requires full file system access with MTP or SFTP using Interop tools
    *All the files attached were taken from the latest AT&T Lumia 950 FFU (01078.00053.16236.35035 - OS 10.0.10586.318)
    *To reset everything back to original factory settings requires either a re-flash or you can take the files you backed up before hand and replace them back.
    **The one caveat to this is you need to use an AT&T Lumia 950 imei to register to your ICCID (sim card ID) with AT&T customer support to enable the hd voice/ims registration to come online. It may work with lets say a Lumia 830 imei for AT&T too. I do not have one anymore to test though.

    Update 7/20/2017: Updated files attached to include the specific ATT-US files from the 950 XL rom RM-1085_15919 (product: 059X7S5). The modem file is slightly different as it provisions with the same bands that come default already on the 950XL, it will not remove band 17 like the 950 ATT modemconfiguration.cab file does. The modem files as far as I know only work on the x50 Lumia models and not OEM models.

    Install Interop Tools
    - Here is the link. I used version InteropTools_1.9.437.0_arm_RC3.

    Install Swish
    - This sftp client found here (needed for Lumia 950/XL) for explorer sftp support. For the IDOL 4s enable Full file system access via MTP with read write access in Interop Tools under the Unlock options/settings.

    Gain access to the file systems using Interop Tools app.
    - In Interop Tools go the SSH--Account Manager and add an account. The account user name should be System.

    - Tap the account System so it is highlighted and then tap templates to use.

    - Tap enable full file system access with sftp. Then go to the template options and hit the authentication drop down setting it to password.

    - Add the password (4 digit pin of your choice).

    - Once your phone is on wifi, add an SFTP Connection under Swish. Set the user to system. Set the path to /c/. Once added double click it and login with the pin you set. Explorer will open with your phones files. There is a guide in more detail on sftp file system access made by snickler if you need to see more details about this method.


    For the Lumia 950/XL do the below:
    - Copy and back up all files under C:\Programs\CommonFiles\ADC\Microsoft and C:\Programs\CommonFiles\ADC\OEM.

    - Then Copy and replace the files under C:\Programs\CommonFiles\ADC\Microsoft and C:\Programs\CommonFiles\ADC\OEM with the files of the zip file titled ADC.zip

    - Copy and backup the file under C:\Programs\CommonFiles\OEM\Public\MMO\Multivariant.

    - Then Copy and replace the file under C:\Programs\CommonFiles\OEM\Public\MMO\Multivariant with the contents of the zip file titled modemconfiguration.zip

    - From there do a hard reset.


    For the Alcatel IDOL 4s do the below using full file system access with MTP:
    - Copy and backup all the files under C:\Programs\CommonFiles\ADC\Microsoft and C:\Programs\CommonFiles\ADC\OEM.

    - Then Copy and replace the files under C:\Programs\CommonFiles\ADC\Microsoft and C:\Programs\CommonFiles\ADC\OEM with the contents of the zip file titled ADC.zip

    - From there do a hard reset.


    When the OOBE setup returns after hard reset, you may have a light blue/cyan theme and the display/dpi/font size may be a bit different too. This is due to the packages used from the AT&T 950. Go through the normal setup and let it fully boot to the start screen. Wait for the prompt to tell you to reboot your phone for settings/sim card settings to change/update.

    Alternatively you can add the two files in the zip file titled MO_VoLTE_1117.zip to the c:\windows\system32. This will replace the MO_VoLTE_Label_1117.dll and MO_VoLTE_Description_1117.dll details found near the volte toggle under Sim settings with the proper descriptions.

    To reset everything back to original factory settings requires either a re-flash or you can take the files you backed up prior and replace them back.

    Thanks to the creator of interop tools @gus33000. Without access to that tool/app this and other things like this would not be possible. To @snickler for finding and explaining the sftp file system access in a guide to help others like me use that method.
    It worked on my Lumia 950 XL
    Look on LumiaFirmware.com for an FFU from your provider (in my case the Lumia 950) mount it with ImgMount and extract the files mentioned above.
    for me no reset was necessary, as soon as I pasted the files in the ADC folder I got a message that "SIM settings have been changed please restart" and IMS registration was on
    That's my findings so far
    1
    I want to enable it for "Jio" a carrier in INDIA that provides VoLTE services but only android and ios users are able to use it and they donot sell a specific lumia with VoLTE services or there carrier name on it.
    *I am using L950XL DS Indian Variant.
    *Is this possible??? If yes can you guide me how to edit configuration files to do this.
    I was mainly referring to US carriers. You would need to get a hold of a Windows 10 Mobile handset that supports VoLTE on Jio and build new nvi file entries for the Lumia. I don't know of a model that would support Jio VoLTE except maybe the IDOL 4s Pro model that support European Countries. Once you find a Windows 10 Mobile phone that supports VoLTE on that carrier you a starting point.
    1
    @spe317
    Since you are reflashing anyway...once you verify all the files are in place. Do full_nvi_update not factory_reset.

    thor2.exe -mode uefiflash -ffufile <ffufile_RM-xxxx.ffu> -do_full_nvi_update -skip_flash -reboot

    This leaves the modem alone as a single sim, and only reintializes the NVI settings with an update from the nvi files.
    If still having an issue you can try a hard reset too. I am not certain why your sim would be doing this...Are you using the Lumia 950 modemconfiguraton.cab file from my first post or are you using the 950 XL files I attached (File Type: zip 950XL_RM-1085_15919_ATT-US_files.zip)
    1
    I had that happen once to an AT&T sim. Except it was not as obvious as yours...my issue was that it would just not lock LTE bands. Took me a week to realize it was due to a bad sim. Glad you caught it quick.

    Just confirmed with ATT and received an IMS lock. Provisioned my phone unbranded 950xl DS. Thanks!