A Short History of VoIP

Today, businesses and consumers are hugely reliant on VoIP for their communications. The technology has been around for several decades, progressing rapidly since the start of the century. Here we take a brief look at the origins of VoIP, paying particular attention to the pioneers.

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Historically, telephone calls used circuit switching; there was a dedicated electronic connection between both ends of the call. The designers of ARPANET developed a different method – packet switching – that allowed multiple connections to share the same link. This BBC article explains their approach: http://news.bbc.co.uk/1/hi/technology/8334233.stm

In 1973 Danny Cohen developed the algorithm for a flight simulator application. He then worked with the ARPANET team to use this technology for sending fast encrypted messages.

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VocalTec was formed in 1989 to research audio products for computers. In 1995 VocalTec launched the Internet Phone, using software that converted the voice signal from analogue to digital, compressed it and split it into packets. Callers would run the VocalTec software on a home computer with a sound card, speakers and microphone.

Manufacturers woke up to the potential of IP telephony. Network specialists such as Cisco developed hardware for routing and switching the IP traffic. Computer software and device manufacturers allowed end-users to use phones as well as computers.


It was essential that the data was transmitted and received according to a common standard for encoding and decoding speech using prescribed codecs. As different manufacturers developed software and equipment at different times, the protocol had to be backwards compatible with previous versions. Historically, two protocols have been used:

– H.323 was initially devised to enable videoconferencing, but was adopted for voice transfer.
– SIP was developed to emulate the features of PSTN calls for IP communications.

VoIP calling plans were introduced around 2004, allowing customers to make inexpensive calls using the internet. Businesses could combine their PBX to offer direct dialling for their customers and partners.

Today VoIP wholesale providers such as https://www.idtexpress.com/blog/category/wholesale-voip are providing high-quality dependable services at economical rates.

VoIP has come a long way in 45 years, from the vision of the ARPANET designers through to the entrepreneurs who saw the business potential. Today VoIP is providing businesses with a cost-effective way to run their communications. Calls are almost instantaneous, with features such as caller ID, and costs can be closely managed.