The early developments of packet network designs by Paul Baran and other researchers were motivated by a desire for a higher degree of circuit redundancy and network availability in the face of infrastructure failures than was possible in the circuit-switched networks in telecommunications of the mid-twentieth century. Danny Cohen first demonstrated a form of packet voice in 1973 as part of a flight simulator application, which operated across the early ARPANET.
It gets even better! Calling internationally using VoIP is far less expensive than using a traditional landline phone company. Every region of the world, from Afghanistan to Zimbabwe, has its own combination of technological development, geographic obstacles, regulations, and taxes. Cell phone carriers, much like VoIP providers, have their own network, which is why it usually costs more to call international cell phones. If a VoIP provider has a significant presence in a country, it’s likely that landline calls will be unlimited with an international package. For example, if you are using Vonage Word, calling from the U.S. to a landline in Germany is included, but it costs US$.0061 per minute to call a cellular phone. If you are using ViaTalk World, you can call both German cell phones and German Landlines for the same rate – free up to 1200 minutes per month. Don’t forget that with every VoIP provider, if you call within their own network, calls are always free no matter where you are in the world. With the development of SIP, you can easily make and receive free international calls from your home using VoIP.
^ Jump up to: a b Mahanagar Doorsanchar Bhawan and Jawahar Lal Nehru Marg (May 2008). "Telecom Regulatory Authority of India (TRAI) Consultation paper on Issues related to Internet Telephony. Consultation Paper No. 11/2008" (PDF). New Delhi India: Telecom Regulatory Authority of India (TRAI). p. 16 (Section 126.96.36.199 PC–to–Phone Internet telephony). Archived from the original (PDF) on October 6, 2014. Retrieved September 19, 2012. An end user is allowed to make PC–to-Phone Internet Telephony calls only on PSTN/PLMN abroad.
In 1999, a discrete cosine transform (DCT) audio data compression algorithm called the modified discrete cosine transform (MDCT) was adopted for the Siren codec, used in the G.722.1 wideband audio coding standard. The same year, the MDCT was adapted into the LD-MDCT speech coding algorithm, used for the AAC-LD format and intended for significantly improved audio quality in VoIP applications. MDCT has since been widely used in VoIP applications, such as the G.729.1 wideband codec introduced in 2006, Apple's Facetime (using AAC-LD) introduced in 2010, the CELT codec introduced in 2011, the Opus codec introduced in 2012, and WhatsApp's voice calling feature introduced in 2015.
Yes it is really this simple. Just connect your telephone adapter to your home Internet by connecting a cable between it and your router or modem. Then connect your existing phone to the adapter and you should be good to go. If you decided to use your own adapter, you will likely be required to run a quick configuration script that is supplied by your service provider.