Why a VPN Works Over Wi-Fi but Not Over Mobile Internet

At home the VPN connects in a second, but the moment you step outside and switch to mobile internet, the connection won't establish or keeps dropping. The situation looks strange: the device is the same, the app is the same, the subscription is the same. But the networks really are different, and that difference is fundamental.

Short answer

Home internet and mobile are two different networks with different equipment along the traffic's path. On a mobile operator, traffic passes through a larger number of intermediate nodes, the route changes more often, the MTU is lower, and filtering is noticeably stricter. That's why a connection that calmly passes over a wire may fail to establish on a cellular network.

How a mobile network differs from a home one

• Shared external address. Mobile operators give subscribers addresses from an internal range and route them outside through a shared gateway. Hundreds of users go online from a single address — and restrictions placed on that address affect them all at once.
• Smaller packet size. In mobile networks the MTU is usually lower than in wired ones. Packets that pass whole at home get fragmented here, and some connections break on this.
• Base-station change. While moving, the device switches between towers, the external address changes, and the established session breaks.
• Different equipment in different regions. The same operator in two cities may filter traffic differently — this isn't a guess, but a consequence of the network being built region by region.

What to try, in order

The list is sorted from the quickest to the longest. The first or second item usually helps.

1. Change the server in the app. The most common solution. If the current location doesn't get through the mobile network, a neighboring one often does.
2. Turn airplane mode off and on. The device re-registers on the network and gets a new address. This helps when the problem is a hung session rather than filtering.
3. Reconnect the VPN instead of waiting. The client may hold a dead connection, thinking it's alive. Disconnecting and reconnecting resets the state.
4. Check that mobile internet works at all. Open any site without the VPN. If it doesn't open either — the VPN isn't the issue: you've run out of plan data, there's no signal, or the operator has restricted access.
5. Turn off data saver and battery saver. Android and iOS can offload background apps and cut network activity. A VPN client offloaded by the system looks like "the VPN doesn't work."
6. Test on another device on the same network. This separates the problem: if everything works on the second device — the issue is in the first device's settings; if not — in the operator's network.

The reverse situation: mobile works, Wi-Fi doesn't

It happens the other way around too, and then the cause is usually the access point itself. Guest networks in cafes, hotels, and offices are often configured strictly: only web ports are allowed, everything else is closed. On a work Wi-Fi, restrictions may be set by the administrator intentionally. It's easy to check — connect to mobile internet: if the VPN works there, the issue is the access point, not the service.

When it's definitely not the app

A sign worth remembering: if the VPN won't connect on several operators at once and on different devices — the conditions on the network have probably changed. If it won't connect only on one operator and only in one place — changing the server almost always helps.

How VolnaLink behaves

The app chooses the connection method for the current network itself — there's no separate protocol switch for the user, and none is needed. If the connection won't establish, start by changing the location: this is exactly the case where a single action solves most situations.

If that didn't help — write to support. No registration is needed for that; we reply on Telegram and by email. It's helpful to state right away the operator, city, connection type (mobile or home), and app version: without this, the investigation takes longer.