How to set up MTS Wi-Fi calling on iPhone: complete instructions with troubleshooting steps

Calls by Wi-Fi from MTS on iPhone — is a lifesaver when the cellular network is weak or completely absent. The technology VoWiFi (Voice over Wi-Fi) allows you to make calls over the internet while maintaining your phone number and connection quality. However, many users encounter issues: the setting doesn't activate, calls are dropped, or the carrier blocks the feature. In this article, we'll look into it. All current methods for connecting MTS Wi-Fi calls to iPhone in 2026, including hidden settings, tariff verification, and troubleshooting.

Important: This technology does not work on all MTS tariffs and requires support from both the operator and the device. If your iPhone older than the model iPhone 6s, the function may not be available. Also check that your router supports the standard. IEEE 802.11ac (or newer) - without this, the connection quality will be unstable.

We tested the instructions on iOS 17.4 And iOS 18 Beta, but the interface may differ slightly depending on the firmware version. If calls don't work after setup, don't rush to blame your carrier: in 90% of cases, the problem lies with incorrect network settings or outdated carrier data.

1. Check compatibility: does your iPhone and MTS plan support Wi-Fi calling?

Before setting up VoWiFi, make sure your device and tariff plan meet the requirements. MTS officially supports the technology on the following models. iPhone:

• 📱 iPhone 6s and newer (including SE 2020/2022)
• 🆔 iOS versions 13.3 and higher (optimally - 15.0+)
• 📡 Tariffs with the "Wi-Fi Calling" option (most modern MTS tariffs)

To check tariff compatibility:

1. Open the app My MTS.
2. Go to the section My Tariff → Services.
3. Find the item Wi-Fi calling or VoWiFi.

⚠️ Attention: If there is no mention of VoWiFiThis doesn't always mean there's no support. Some plans activate the feature automatically when you first sign up. Try setting up calls manually—if your plan doesn't support the technology, your iPhone will display an error. "Unable to connect to the operator's network".

Also, check that MTS offers this service in your region. In remote areas or on corporate plans VoWiFi may be disabled. You can check availability through MTS support chat or by calling 0890 (call is free).

2. Step-by-step setup of MTS Wi-Fi calling on iPhone

If your device and plan are compatible, let's move on to setup. These instructions apply to all current versions. iOS (from 15.0 to 18.0).

Open Settings on iPhone and follow these steps:

1. Go to Cellular communications (or Mobile communications on some firmware).
2. Select SIM card settings (if you have an eSIM, tap on the operator name).
3. Find the item Wi-Fi calling and move the slider to the right.
4. In the window that appears, confirm the activation by clicking Turn on.

After this, your iPhone will attempt to connect to the MTS network via Wi-Fi. This process may take up to two minutes. If the connection is successful, the following message will appear in the status bar next to the operator's name: MTS Wi-Fi.

Make sure your iPhone is connected to Wi-Fi|Check your balance (must be at least 10₽)|Update iOS to the latest version|Restart your phone before setup-->

If the slider Wi-Fi calling inactive (gray color), this means one of the problems:

• 🚫 The tariff is not supported VoWiFi (solution: change tariff or contact MTS).
• 🔄 The SIM card is not activated for the service (solution: restart the iPhone or reinstall the SIM).
• 📶 Poor Wi-Fi signal quality (solution: connect to a different network).

⚠️ Attention: On some firmware (iOS 16.0–16.3) after switching on VoWiFi Mobile data may drop out. This is an Apple bug that has been fixed in newer versions. Update iOS if you encounter this issue.

3. Updating operator settings: why it's critical for VoWiFi

Even if you turned it on correctly Wi-Fi calling, they may not work due to outdated operator settings. MTS periodically updates the configuration for VoWiFi, and if your iPhone has not received this data for a long time, the function will be blocked.

To update settings:

1. Open Settings → General → About.
2. Scroll down to the section Operator version.
3. If the version is outdated (for example, MTS 42.0 at the current 45.1), return to Main.
4. Select Software update and wait for verification.
5. If an operator settings update is available, install it.

After updating, restart your iPhone. This will clear the communication module cache and apply the new settings. If there are no updates, but VoWiFi If it doesn't work, try resetting your network settings:

Settings → General → Transfer or reset iPhone → Reset → Reset Network Settings

This procedure will delete all saved Wi-Fi networks and passwords, but often solves problems with connecting to VoWiFiAfter the reset, reconnect to Wi-Fi and check your calls.

4. Solving typical errors when connecting to MTS Wi-Fi calls

Even after proper setup VoWiFi Glitches may occur. Let's look at the most common errors and how to fix them.

If you hear a message when you call "The subscriber is temporarily unavailable.", but in fact the number exists, the problem may be in DNS servers your router. Try manually entering Google's DNS:

8.8.8.8
8.8.4.4

To do this:

1. Open Settings → Wi-Fi.
2. Tap on the icon i near your network.
3. In the section DNS select Manually and add addresses.

What to do if VoWiFi works but the connection quality is poor?

If your voice is interrupted or there is interference, the problem may be:

- Overloaded Wi-Fi channel (change the channel in the router settings to 5 GHz).

- Low internet speed (check the speed on Speedtest — for stable calls you need at least 1 Mbit/s).

- Outdated router firmware (update the router software via the web interface).

5. Configuring your router for stable VoWiFi operation

Quality Wi-Fi calling It directly depends on your router settings. If the signal is weak or the router blocks certain ports, calls will be dropped or not connect at all. Here are the key parameters to check:

• 📶 Wi-Fi standard: must be 802.11ac or 802.11ax (Wi-Fi 5/6). Old standards (802.11n) may not provide sufficient speed.
• 🔒 Security type: only WPA2-PSK or WPA3. Outdated WEP not supported.
• 🔄 Frequency range: For better stability, use 5 GHz (less busy than 2.4 GHz).
• 🚪 Ports: must be open UDP 500 And 4500 (for IPSec, which MTS uses for VoWiFi).

To open ports on your router:

1. Go to the router's web interface (usually at 192.168.1.1 or 192.168.0.1).
2. Find the section Port Forwarding or Virtual server.
3. Add two rules:

   Protocol: UDP, Port: 500, IP: [your iPhone's IP]
   Protocol: UDP, Port: 4500, IP: [your iPhone's IP]

4. Save the settings and reboot the router.

If you don't know your iPhone's IP address, you can find it in Settings → Wi-Fi → [your network] → IP addressPlease note that the IP address may change when reconnecting to the network. For stable operation, it's best to assign the IP address to the device in the router's DHCP settings.

⚠️ Please note: Some providers (eg. Rostelecom or Beeline) block ports by default. If VoWiFi doesn't work after setup, contact your internet provider's technical support and check if traffic is allowed. UDP 500/4500.

6. Alternative ways to make calls over Wi-Fi if VoWiFi doesn't work

If standard VoWiFi I can't set it up with MTS. There are alternative options for making calls over the internet:

• 📞 MTS Connect — the official MTS app for Wi-Fi/4G calling. It works even on older iPhones and doesn't require VoWiFi support on your plan.
• 💬 WhatsApp/Telegram — calls via instant messaging apps. Disadvantage: the caller must also use the same instant messaging app.
• 🌍 Skype/Zoom — universal solutions for international calls.
• 📱 Google Voice — If you have a Google account, you can get a virtual number for calls.

To use MTS Connect:

1. Download the app from App Store.
2. Log in with your MTS number.
3. Enable the option in the settings Internet Calls.
4. Now you can call any number, even if VoWiFi is disabled.

Advantage MTS Connect before standard VoWiFi:

• Works on all tariffs (even old ones).
• Does not require special router settings.
• Supports video calls.

However, there are some drawbacks: calls made through the app may be charged differently than regular calls. Check the terms in your MTS account or by calling the number. 0890.

7. How to check that MTS Wi-Fi calls are working correctly

After setup VoWiFi It's important to make sure that calls are actually made over Wi-Fi and not the cellular network. Here's how to check:

1. Turn on on iPhone Airplane mode.
2. Activate only Wi-Fi (cellular communication must remain switched off).
3. Try making a call. If it connects, VoWiFi is working.

Also pay attention to the following indicators:

• 📶 The following message appears in the status bar next to the operator's name: MTS Wi-Fi.
• 📞 During a call, an icon is displayed in the top bar Wi-Fi instead of cellular antennas.
• 🔊 The connection quality should be better than on a cellular network (no interference, echo).

If the call does not connect in Flight mode with Wi-Fi turned on, that means, VoWiFi not activated. Go back to settings and repeat the steps from Section 2.

For more detailed diagnostics, you can use the hidden menu iPhone:

1. Open the app Telephone.
2. Dial *#31# and press "Call".
3. If a message appears "Disable Caller ID", then VoWiFi is active.

⚠️ Attention: In some regions MTS may limit VoWiFi For international calls. If you try to call internationally via Wi-Fi and the connection drops, check with your carrier.

FAQ: Frequently asked questions about MTS Wi-Fi calling on iPhone

❓ Can I use VoWiFi abroad?

Yes, but with some caveats. Wi-Fi calls will be charged as outgoing calls from a Russian number, even if you're roaming. Check international call rates in your MTS account. Also, make sure your local carrier isn't blocking ports. UDP 500/4500.

Why did the "MTS Wi-Fi" icon disappear after updating iOS?

This is a known issue after updates. iOS. Solution:

1. Open Settings → Cellular → SIM card options.
2. Turn it off and on again Wi-Fi calling.
3. Restart your iPhone.

If it doesn't help, reset your network settings (Settings → General → Reset → Reset network settings).

❓ Will VoWiFi calls be charged like regular calls?

Yes, Wi-Fi calls are charged at the same rates as regular calls. The exception is if you use instant messaging apps (e.g., WhatsApp), where calls are free, but the subscriber must also be in this messenger.

❓ Is it possible to enable VoWiFi on an iPhone with two SIM cards?

Yes, but only for one SIM card at a time. To choose which SIM card to activate VoWiFi for:

1. Go to Settings → Cellular.
2. Select the desired SIM card.
3. Turn on Wi-Fi calling for her.

For the second SIM card the function will be disabled.

❓ Why does VoWiFi only work on certain Wi-Fi networks?

It depends on your router settings. Some public networks (such as those in cafes or airports) block the ports needed for VoWiFi. The issue could also be related to the network security type: VoWiFi doesn't work on open networks (without a password) or with outdated encryption. WEP.