Here you can also make free cell phone calls with members (or friends)... from your city or even worldwide!
With WhatsApp you can not only write and send files, but also make phone calls. The best thing about it:
the conversations don’t cost any money! At least not directly. And that's precisely why you should know a
few things before making a call via WhatsApp (which, by the way, also applies to other services such as Skype,
Google Hangouts or Apple Facetime).
The phone calls are made over the Internet. The technology is called Voice over Internet Protocol (VoIP). This means:
All conversations take place via servers, which in the case of WhatsApp are located all over the world. It is possible
that your phone calls also go through servers in the USA. Since April 2016, WhatsApp has had end-to-end encryption,
which is intended to make conversations tap-proof. But only the content is encrypted. The operator can theoretically
keep track of when you talk to whom on the phone and for how long.
Because telephone calls are made over the Internet, you use up data volume with every call - regardless of whether you are calling someone or are being called. So if you're not on WiFi somewhere, you can use your mobile high-speed volume. There are different statements about how much data a VoIP phone call requires - ultimately it also depends on the quality of the call. You should expect around 1 to 1.5 megabytes (MB) per minute of conversation.
Be careful, of course, on vacation: Mobile data use abroad is extremely expensive if you use a German SIM card! Unless you are in an EU country. Since mid-2017, you have been able to use your smartphone tariff just as you would at home. And if you are in another country, it is often worth purchasing a prepaid card from a provider in the relevant country.
https://www.checked4you.de/handy-telefon/messenger/telefonieren-mit-whatsapp-351171
