What is VoIP or "Voice Over Internet Protocol" and how can it be used ? There are too many specs, standards and acronyms, so we want to collect the main knowledge to prepare a discussion or decision with basic knowhow.

If you currently call a friend or any person in a foreign country, your voice will be transported over an switched telco network. Mostly it is a dedicated telco network with dedicated voice swichtes with no extra use beside the voice channels.

What is a shortform of VoIP :

But now, we have an extremely oversized IP lines bandwidth on almost all continental and intercontinental internet lines, so that people ask for cheaper communication. So let us talk over this simple and cheap way from PC to PC or from any phone to any IP phone.

That was the initial start for VOIP. It must be cheaper and it must be worldwide. It must be understandable and hardware and software must be affordable. US citizens are much more tolerant having low-cost low-performance wide area calls than most Europeans. Europe has a very high quality ISDN telco infrastructure on a very high (High Fidelity) sound and voice quality. No echo, no hum, no noise at all, like FM radio.