If you could theoretically build a laptop so that you in the example. In the German landline or in all mobile networks can make calls?

So apart from Skype and what else is there for Vodeoübertragung, I mean pure telephony? (ps If this technology already exists, please excuse my ignorance) Thank you

That works with any laptop, if you install the right software.

If the laptop has a cellular module, it's really just a software issue. A modern smartphone is nothing more than a small, flat computer.

Of course you can. But it is not easy.

You need in the laptop / Raspi once a transmitter and a receiver. These things can be ordered, preferably in China. China is technologically advanced and sometimes has a choice that does not yet exist in Europe.

Then you have your dial-up instrument.

The next step is to let you run the nets. You can e.g. Dial in with the router and then? Then you need a password to connect you to a server and connect to the network.

The same problem you have with every single network.

What exactly a phone card must include, you can find on the Internet. Search for specification. If you know more about crafting then google for Marker Faire.

I have not seen a laptop with a simcard holder, but you can retrofit it. Then just the right software and you can call the phone via mobile anywhere.

Alternatively via Spipgate o. Ä. VOIP services. You then only need an Internet line (can also be via mobile or just WLAN / DSL) and then call.

Pure telephony is relative, since there are no more classic analog ports.

It's all about the so-called Voice over IP these days, i. Internet, so that you can use any laptop as normal for calling, if you have the right software.

Why so complicated? Buy Surfstick with Sim card, order a Sipgate VOID connector. Already call and be called worldwide.

Let's keep quiet about the meaning and the costs.

In business laptops more SIM slots (for mobile Internet) are installed.