How to Make a Call over Wi-Fi: A Complete Guide to Setting Up VoWiFi

Calls via Wi-Fi (or VoWiFi) is a technology that allows voice calls to be made over the internet rather than over a cellular network. It's especially useful in areas with poor mobile coverage but stable Wi-Fi: basements, tall buildings, country houses, or even abroad. The phone number remains the same, and the call quality is often better than traditional calls.

In this article we will look at how to enable VoWiFi on Android And iPhone, what requirements Russian operators (MTS, Beeline, Tele2, MegaFon) have, and what to do if the function doesn't work. We'll also explain how VoWiFi differs from ViLTE (4G calls) and messengers like WhatsApp—and why the former is more reliable for emergency calls.

What is VoWiFi and how does it work?

VoWiFi (Voice over Wi-Fi) — a communications standard that transmits voice traffic over the internet instead of cell towers. The technology is based on the protocol IMS (IP Multimedia Subsystem) and is supported by most modern smartphones. Key advantages:

• 📶 Stability: works even in the absence of a mobile network signal, if there is Wi-Fi.
• 💰 Saving: calls are charged as usual (without additional charges for roaming in some cases).
• 🔊 Quality: less interference and interruptions than with weak 2G/3G signal.
• 🚨 Emergency calls: Unlike instant messengers, VoWiFi allows you to make calls 112 or 911 with location determination.

It is important to understand that VoWiFi is not the same, that calls through WhatsApp, Viber or SkypeThe latter are app-dependent and require the other party to be online. VoWiFi, on the other hand, is integrated into the standard phone module and works like a regular call, but over the internet.

Technically the process looks like this:

1. The smartphone connects to Wi-Fi.
2. When making an outgoing call, the signal is sent not to the nearest tower, but to the operator's server via the Internet.
3. The operator routes the call to the regular telephone network (or to another VoWiFi user).

⚠️ Please note: Not all operators support VoWiFi while roaming. Check your plan's terms and conditions—some may block the feature abroad or charge additional fees.

Requirements for Wi-Fi calling

To use VoWiFi, you need to meet four key conditions:

Critical note: if your operator does not support VoLTE, then VoWiFi will not work either - these technologies are interconnected. You can check support in your personal account or via a USSD command (for example, *111*58# for Beeline).

Also make sure that the protocol is enabled on the router. IPv6 — Some operators require it for VoWiFi to work properly. You can check this in the router settings section. Local Area Network (LAN) → IPv6.

How to enable VoWiFi on Android

The instructions may differ slightly depending on the phone model and version. Android, but the general algorithm is as follows:

1. Open Settings → Connections → Mobile network (or SIM cards and mobile networks).
2. Select your SIM card (if you have more than one).
3. Find the item Calls via Wi-Fi or VoWiFi and activate it.
4. In some phones (eg. Xiaomi) must be additionally enabled Enhanced 4G (VoLTE).
5. Restart your phone if the feature does not appear immediately.

On Samsung Galaxy the path may look like this:

Settings → Connections → Mobile networks → [Select SIM] → Wi-Fi calling

If the item is not in the menu, check:

• 📱 Update your phone firmware to the latest version.
• 🔄 Reinstall your SIM card (sometimes resetting network settings helps).
• 📋 Make sure your carrier supports VoWiFi for your plan.

Update your phone's firmware|Check your carrier's VoLTE support|Enable VoLTE in settings|Restart your device-->

⚠️ Attention: On some custom firmwares (for example, LineageOSVoWiFi may not work even if supported by the hardware. In this case, only the official firmware will help.

How to enable VoWiFi on iPhone

On iPhone Setting up VoWiFi is easier, but requires iOS 12 or newer. Follow the instructions:

1. Go to Settings → Cellular.
2. Select Data and voice parameters (or Cellular data → Parameters).
3. Activate the switch Calls via Wi-Fi.
4. In the window that appears, click Turn on.

If the option is inactive:

• 🔄 Update iOS to the latest version.
• 📋 Check if your operator supports VoWiFi (on iPhone The function may be hidden if the operator does not provide it).
• 🔄 Restart your phone and try again.

On iPhone You can also enable the option Wi-Fi calls while roaming (in the same menu), but it may be charged differently - check with your operator.

Configuring a router for stable VoWiFi operation

Even if your phone and carrier support VoWiFi, problems can arise due to incorrect router settings. Here are the key parameters to check:

• 🔄 IPv6 protocol: must be enabled (in most cases the mode is sufficient) Automatic or DHCPv6).
• 🔒 Firewall: should not block ports 500, 4500 (for IPSec) and 5060-5061 (for SIP).
• 📶 Qos (Quality of Service): Prioritize voice traffic to avoid delays.
• 🔄 Wi-Fi operating mode: For better stability, select 802.11ac (5 GHz) or Wi-Fi 6.

Example of setup Qos on the router TP-Link:

Advanced settings → QoS → Enable QoS → Prioritize by application → Add rule for "VoIP"

If you have a dual-band router, connect to the network 5 GHz - it is less loaded and provides lower ping, which is critical for voice communication.

Common problems and their solutions

VoWiFi may become unstable for a variety of reasons, from operator errors to phone settings. Let's look at some typical scenarios:

Problem 1: VoWiFi won't turn on (gray switch)

• 📱 Make sure your SIM card supports VoLTE (check in your operator account).
• 🔄 Update your phone firmware.
• 📋 Insert the SIM card into the slot SIM1 (on some phones VoWiFi only works with the main card).

Problem 2: Calls go through, but the sound is interrupted

• 📶 Check your Wi-Fi speed (it should be at least 2 Mbps).
• 🔄 Reconnect to the network or reboot your router.
• 🎧 Turn off Bluetooth devices as they may cause interference.

Problem 3: VoWiFi works, but not when roaming

Some carriers disable VoWiFi abroad. Check your plan's terms or use a local SIM card that supports this feature.

Why might VoWiFi not work with a VPN?

VoWiFi uses the IMS protocol, which some VPN services block as "insecure traffic." If you're connected to a VPN, try disabling it or adding an exception for IMS traffic in your VPN app settings.

⚠️ Note: If your phone's battery drains quickly after enabling VoWiFi, disable the feature in the battery saving settings. Some manufacturers (e.g., Xiaomi) aggressively optimize background processes, which interferes with VoWiFi.

VoWiFi vs. ViLTE vs. Messengers: Which is Better?

Many people confuse VoWiFi with other methods of voice communication over the internet. Let's explore the key differences:

The main advantage of VoWiFi over instant messengers is reliabilityThe call goes through the operator, not through the third-party app's servers, so:

• 🚨 You can call emergency numbers (112, 102 etc.).
• 📞 The person you're talking to will see your real number, not your messenger account.
• 🔄 Less connection delays (no dependence on WhatsApp/Viber servers).

However, if you need free international calls, instant messengers will remain the best choice.

FAQ: Answers to frequently asked questions

Is it possible to use VoWiFi without a SIM card?

No, VoWiFi is tied to your SIM card and carrier plan. Without an active SIM card, the feature won't work (unlike messaging apps).

Will VoWiFi work abroad?

Depends on the carrier. Some (for example, MTS) support VoWiFi while roaming, but may charge an additional fee. Check your plan's terms.

How can I check if a call is made via Wi-Fi?

On Android: During a call, an icon will appear in the status bar Wi-Fi with a pipe. On iPhone: there will be an inscription in the upper left corner "Wi-Fi" next to the operator's name.

Why doesn't VoWiFi work with two SIM cards?

Most phones support VoWiFi only for the primary SIM (usually SIM1). Try swapping the cards or disabling the second SIM in the settings.

Is it possible to make calls via VoWiFi on a tablet?

Only if the tablet supports SIM cards and VoLTE/VoWiFi (e.g. Samsung Galaxy Tab S7+). This function is not available on Wi-Fi-only tablets.