[Google Pixel 2 Guides, News, & Discussion] somin.n:
Hi :) Let me introduce tutorial, how to enable VoLTE/VoWiFi for some other carriers. All credits goes to @Airpil for his great work with enabling diag port for Pixel 2 phones and to @topjohnwu for his original Magisk project.

UPDATE:

Here is another way by @Vortuks , how to get things working.

https://github.com/stanislawrogasik/Pixel2XL-VoLTE-VoWiFi

ANOTHER UPDATE:

On Android 11 you can use module VoLTE_enabler_pixel_2_v1_1.zip, but you will myabe need to use SeLinux permissive module too.

BIG UPDATE:

use only on PIE

for android 10 use solution with PDC tool

I created new magisk module with everything needed for enabling VoLTE. Just install VoLTE_enabler_pixel_2_v1_1.zip and enjoy.

this will work only, if there is proper *.mbn for your provider

sometimes is needed to remove/add module after updating monthly updates

sometimes is needed to toggle off/on enhanced 4g LTE mode and go to airplane mode and back

Prerequizites:

your carrier have to support this feature

and you have to enable this feature on operator's side

PC with windows

you must have some luck

Prepare your PC:

google for QPST_2.7.474 and install it

install provided drivers (if they willn't work, google for better)

from provided nokia_mbn_files.zip find the right mcfg_sw.mbn for your carrier, if there isn't any mbn for your carrier, you can try another one, but without warranty

Prepare your phone:

backup everything, what you can :D especially EFS partition - just for sure ;)

root your phone with provided Magisk.zip

boot up your phone

In Magisk Manager app find and install VoEnablermodule, restart phone

there will be new settings under Settings-Network & internet-Mobile network-Advanced

connect phone to PC and set to charge only mod

in terminal emulator run this commands (this will enable diagnostic port on phone):

su
setenforce 0
setprop sys.usb.configfs 1 && setprop sys.usb.config diag,serial_cdev,rmnet_gsi,adb

Next steps:

find PDC tool from installed QPST and open

select device from drop-down menu, if it is empty, you will have to reinstall/choose another driver

click load button and find prepared mcfg_sw.mbn file

now right-click on new loaded profile and select SetSelectedConfig - Sub0

and now button Activate

activate provided VoEnabler module via MagiskManager

restart device

and now, if you are lucky one, your VoLTE is working :victory:

Final steps:

if everything is working, you should reinstall original Magisk from twrp

Troubleshhoting:

99,9% of all problems comes with wrong driver

open windows device manager and try to choose another driver for HW like:

Qualcomm HS-USB Modem 9091

Qualcomm HS-USB Diagnostics 9091

Qualcomm HS-USB WWAN Adapter 9091

Is it working?

dial *#*#4636#*#*

Phone information-3dots-IMS service status

If IMS Registration: Registered and Voice over LTE: Available you won

after update with factory images you will have to re-do this steps

Confirmed carriers:

Czech T-mobile

VoLTE - yes

VoWiFi - no

Poland Orange(confirmed by @saperkus)

VoLTE - yes

VoWiFi - yes

Poland Play(confirmed by @saperkus)

VoLTE - yes

VoWiFi - yes

Telenor Bulgariawith Telenor Danemark mbn (confirmed by @pavel5044)

VoLTE - yes

VoWiFi - no

T-Mobile Hungary (Telekom)(confirmed by @hunfatal)

VoLTE - yes

VoWiFi - no

Downloads:

Drivers:
[url]https://mega.nz/#!oMEHTIbA!0g7ahr8r81Q3ue8LpEy-sfd7FTLEEQlGRi2CJfG_Kq0[/url]