What Was The First Internet Phone Call?

Article By Stephen McClelland

18/06/2024

One of the biggest motivators for many customers looking for a better business broadband solution is the increasing reliance on teleconferencing and video calls.

Whilst a decade ago it would have been standard to have a switchboard and a large connected network of telephones at each desk, the need for flexible, mobile alternatives has led to a switch towards technologies such as Voice over Internet Protocol (VoIP).

At a basic level, VoIP converts voice into digital signals that allow you to make calls over the internet, but it tends to specifically refer to services and technologies that allow an online user to send and receive telephone calls throughout the phone network, not only to other internet phone users but also across phone lines and to mobile phones.

VoIP was the big catalyst for companies to switch to high-speed internet, as it allows for teleconferencing and more flexibility in how people work, and is a big reason why broadband is a primary marker for the digital divide.

However, the concept of making a phone call over the internet is much older than this, and in fact, turns 50 years old this year. Here is why.

From Goleta To Massachusetts

The origin point for VoIP technology is the concept of linear predictive coding (LPC), which is the most commonly used method for digitising speech into signal and code.

It was first theorised as early as the 1940s and applied to speech in 1966 by Nippon Telegraph and Telephone’s Shuzo Saito and Nagoya University’s Fumitada Itakura and Shuzo Saito.

This concept formed the basis for packet speech, where these LPC speech signals were distributed over a computer network, with the earliest developments in that direction being started by Bob Kahn, then at DARPA, Lincoln Laboratory’s Jim Forgie and BBN Technologies’ Dave Walden.

Lincoln Laboratory claimed to have developed the first real-time application of LPC thanks to the work of Ed Hofstetter, but this was only half of the puzzle. It could digitise speech in real-time, but could it read and interpret someone else’s speech at the same time?

However, other sources claim that the first application of the concept was by Danny Cohen.

Ultimately, the first two-way communication system was developed the following year in the form of Network Voice Protocol, which operated on ARPANET, an early forerunner of the Internet.

After its first successful demonstrations of concept, an actual phone call over a computer network was made in August 1974, between members of the team at the Information Sciences Institute, based in Goleta and part of the University of Southern California, and MIT Lincoln Laboratory.

The call, between Randy Cole and Jim Forgie, took place using a device that transmitted information at 8 kilobits per second, which is a seventh of the speed of dial-up, and many orders of magnitude lower than the typical high-speed broadband connections used today.

A lot of contemporary reports of the call put it in quotation marks, as whilst Randy and Jim could recognise each other’s voices, the call quality was so low that they could not work out what they were saying to each other.

However, the real victory was the proof of concept, and this went on to become the cornerstone of the modern agile online business.