We increasingly get calls from businesses looking for a more reliable way to receive their incoming business calls. In practice they are often using a special app on their mobile to take those calls, and calls regularly go missing. That does not surprise us, and in this article we explain in plain language why it happens and what the pros and cons really are.

What is a softphone?

To be clear: we can also deliver calls over the internet (the VoIP protocol) to a so-called softphone. That is an app installed on the user’s smartphone or computer, and we see this method being offered more and more by internet companies.

The big advantage is obvious: your business and personal calls stay separate. You have a business number on your own mobile, and since there is an app for everything these days, it sounds like the perfect solution.

Why calls go missing

There are serious catches you rarely read about. Calls through such an app regularly fail to arrive, or arrive badly. The reason is that they do not travel over the voice network of your mobile provider, which is built for exactly this, but over the data network. Your provider does not recognise them as phone calls, only as a stream of internet packets, so a voice call is being forced over a data connection to an app, and things can go wrong at several points.

The sleep mode problem

The only app on your phone that is truly tuned to receiving calls is the phone app that came with the handset. It is fully integrated with the battery, the firmware and the operating system, so an incoming call over the normal network gets absolute priority. Mobile operators invest billions every year to make that work flawlessly.

Alternative calling apps miss that integration. When a call is waiting for you in such an app, our platform first has to send a push notification to wake the app up, which is in effect a workaround. Only once the app is awake, and that does not always happen straight away, is a voice connection set up over the internet. The call quality then depends entirely on how stable your 4G, 5G or Wi-Fi connection is at that moment.

We estimate that up to 20% of calls can be lost this way, and the worst part is that the user often does not know. If the app is asleep, the call is not registered at all, so you do not even see a missed call notification.

On the move, an app does not know where you are

There is a second problem, which matters most if you are often on the road. You switch networks all day: from the office Wi-Fi to 4G in the car, to 5G in town and to the Wi-Fi at a client’s office. Every switch changes your phone’s internet address, so at the moment a call comes in our platform cannot be sure where your app is. Offering the call to the app is always something of a gamble.

That up-to-date location information is exactly what mobile networks excel at. Your phone keeps checking in with the masts nearby, so the network always knows which area you are in. That is also one of the reasons all those masts need so much capacity: not only for the calls taking place, but also to keep track of where every phone is. When a call comes in, the network sends it straight to the right masts and your phone rings.

Compare that with a VoIP app that does not know. It may be in sleep or battery-saving mode and has to wake up first, then make contact with the telephony platform, and then send the voice over an internet connection that has just switched from Wi-Fi to 4G. Every step takes time, and at every step the call can be lost.

What VoIP needs to work properly

That does not mean VoIP is bad. At a fixed workplace it works very well, as long as a few things are in place. That is why most VoIP solutions are sold by IT companies, which present VoIP as part of a complete package to keep your IT running. Such a package usually has four parts:

  1. A fixed internet connection, ideally full fibre, with enough bandwidth and stable quality.
  2. A static IP address, so the telephony platform always finds your connection at the same address.
  3. A good firewall, which decides what may and may not enter your network and is set up so that voice traffic gets priority rather than being blocked.
  4. A support contract, so you have someone to call when it stops working.

With those parts in place, for example at the office with a desk phone, VoIP will work well, and it is also the cheapest way to deliver calls. If you are often on the move, you cannot meet these requirements by definition, because you have no fixed connection, no static IP address and no firewall managing your mobile connection.

When does a softphone make sense?

This is not a blanket complaint about VoIP apps, because they have their uses. One of our customers organises hiking trips in the Canary Islands, in mountains without mobile coverage but with internet via satellite. In that situation a softphone is ideal, and that is how we deliver the calls.

For customers who want or need a softphone, we offer Linphone: a reliable, open-source softphone from France. Because the code is open source, IT managers can see exactly what software runs on their staff’s phones. On a desktop or laptop that is on all day, it is reliable and can fully replace a desk phone. In the UK and the rest of Europe, where the mobile voice networks are excellent, there is no need to take the risk of an app on a mobile phone.

Think like a business owner

You may be paying several pounds per click on Google Ads, so it can easily cost you £40 to £80 in marketing budget before a potential customer actually picks up the phone. Do you really want to risk that expensive call disappearing over a patchy data connection? A call we deliver over the mobile network costs a few pence a minute more than over the internet. Weigh those few pence against an important lead or business contact who is calling, and the choice is quickly made.

At the office, with a fixed connection and good IT, calls can come in over the internet, and on the move you have them delivered to your phone over the mobile network with a landline number on your mobile. With CallFactory you combine the two, so you only pay for the premium route when it matters.