Wi-Fi (VoWiFi) calls on the Xiaomi Redmi Note 8 Pro are a technology that allows voice calls even when you don’t have a mobile network using an internet connection. Especially for places with poor 4G/3G coverage, such as basements, country houses or thick-walled offices. But not all operators support this feature, and in MIUI settings it is often hidden or requires additional activation.
In this article, you will find a step-by-step guide to the Redmi Note 8 Pro (begonia model), check compatibility with your tariff, and solve typical problems: why the option does not appear on the menu, how to fix the “failed to connect” error and what to do if calls are interrupted. We tested all the steps on MIUI 12.5-14 firmware (including the global and European versions).
What is VoWiFi and why it doesn’t work out of the box
Voice over Wi-Fi (VoWiFi) technology is transferring voice traffic over an Internet connection instead of a cellular network.
- 📶 Stable signal in areas with poor coverage (for example, in the subway or on the lower floors)
- 💰 Battery savings – the phone doesn’t search for the network all the time
- 🌍 International calls at home rates (if the operator supports VoWiFi roaming)
However, on the Redmi Note 8 Pro, the feature is often disabled by default, even if the operator supports it.
- ⚙️ There is no certification for some regions (for example, in Russia VoWiFi officially launched only at MTS, Beeline and MegaFon from 2022).
- 📱 Firmware MIUI This option can be blocked due to regional restrictions (especially on Chinese versions of the phone).
- 📡 Incompatibility with SIM-map: Support is required IMS (IP Multimedia Subsystem on the operator side.
Before setting up, check if your tariff supports VoWiFi.
- Open the operator’s website and search for the “Services” section → “Calls over Wi-Fi”.
- Or send it. USSD-request: MTS: *111*464# Beeline: *110*180# MegaFon: *105*495#
Verify VoWiFi support on Redmi Note 8 Pro
Not all versions of the Redmi Note 8 Pro support VoWiFi, here’s how to find out if the feature is available on your device:
- Model and firmware check: Go to Settings → About Phone → MIUI version. VoWiFi works on: Global (MIUI Global) and European (MIUI EU) firmware version 12.0.1+. Chinese firmware (MIUI China) only with manual inclusion through the engineering menu.
Verification SIM-map
Insert the SIM into a SIM 1 slot (VoWiFi often doesn't work in the second slot). Make sure the card supports 4G VoLTE - without this, VoWiFi won't work.
Test challenge
Connect to Wi-Fi, turn off your mobile data, and try calling. If the call doesn't pass, the function is disabled.
| Firmware | Support for VoWiFi | Is manual activation required? |
|---|---|---|
| MIUI Global 12.5+ | ✅ Yes. | ❌ No (includes in settings) |
| MIUI EU 12+ | ✅ Yes. | ❌ No. |
| MIUI China | ⚠️ Partially. | ✅ Yes (via engineering menu) |
| Custom ROM (LineageOS, etc.) | ❌ No. | — |
⚠️ Note: If you use Redmi Note 8 Pro with firmware from a third-party developer (e.g. Pixel Experience), VoWiFi will probably not work – original drivers are required. IMS Xiaomi.
Step-by-step: how to turn on VoWiFi
If your operator and firmware support the technology, follow this instruction:
Connect to a stable Wi-Fi network (2.4 GHz or 5 GHz)
Put it in. SIM-slot-card
Update the firmware to the latest version
Check balance (some carriers block VoWiFi when negative balances are in place)-->
- Open the settings. SIM-Maps: Go to Settings → SIM-maps and mobile networks → [Yours. SIM-map] → Calls over Wi-Fi. If there's no point, it's hidden. Continue from the next step.
- Activate via Engineering Menu (if not available): Open the Phone app and type the combination: ##869434## In the menu that appears, select IMS Service Menu → VoWiFi → Enable. If the menu does not open, your firmware does not support this method.
- Enable in hidden settings (alternative way): Install Star Code from Google Play. Enter the code: ##4636## Go to Phone information → Wi-Fi Calling → Enable.
- Phone Reboot: Once turned on, be sure to restart the device - the changes will only take effect after the reboot.
Critical detail: if after activation in the status bar did not appear icon "Wi-Fi Calling" (phone handset with waves), then the operator does not support the function or requires additional settings on its side.
Problem Solving: VoWiFi is not working
If Wi-Fi calls are not turned on or interrupted, check these points:
- 🔄 Reconnect to Wi-Fi: sometimes changing the network (for example, from 5 GHz to 2.4 GHz) helps).
- 📱 Reset network settings: Settings → System system → Reset → Resetting Wi-Fi, Mobile Network and Bluetooth.
- 🔧 Update your operator profile: Open Settings → SIM-maps and mobile networks. Choose your own. SIM-map → Access point (APN) → Click on three dots in the upper right corner → Resetting to default values.
Check the IMS settings
How to open IMS settings on Redmi Note 8 Pro
| Problem. | Possible cause | Decision |
|---|---|---|
| The option “Calls over Wi-Fi” is not in the settings | The firmware does not support VoWiFi. | Update MIUI or use the Engineering Menu |
| Calls are interrupted in 10-20 seconds. | Unstable Wi-Fi connection | Connect to another network or restart your router |
| The interviewer can't hear you. | Codec problems (usually OPUS) | Turn off VoWiFi and use the mobile network |
| VoWiFi icon is there, but calls go through the mobile network | The operator has not activated the service on your number. | Contact the operator for support |
⚠️ Note: Redmi Note 8 Pro with firmware MIUI China, after manually turning on VoWiFi, can lose mobile Internet. IMS Initial state or run a global version MIUI.
How to turn off VoWiFi (and why you might need it)
In some cases, it is better to turn off calls via Wi-Fi:
- 🔋 Increased battery consumption – constant transmission of voice packets discharges the battery faster.
- 🎤 Poor sound quality – if you have slow Wi-Fi (below 5 Mbps), your voice may be interrupted.
- 🌐 Roaming – some operators block VoWiFi abroad.