Before the Dawn of IP Telephony - Part 1
Uphill battle for the development of the first IP telephony (1995 ~ 1996)
These contents translated a serialization article carried by ITPro IP telephony ONLINE published by Nikkei Business Publications, Inc. Jump to the original (Japanese).
Shinji Usuba
General Manager
eSound Venture Unit
Business Incubation Division
Systems Network Group
Oki Electric Industry Co., Ltd
Handling voice over an IP network-a concept that seems somewhat of common sense at the present with the widespread of IP Telephony was a challenge that was simply unheard of 10 years ago. It was about then when I first started the development of IP telephony related products. Here's a review of the efforts at the time.
Photo 1 : OKI's booth at NET&COM 2004
Half of the display booth was dominated by e-Sound IP phones, realizing voice quality that surpasses conventional telephones.
At "NET&COM 2004," an exhibition held in February 2004 in Makuhari, Chiba, OKI displayed the e-Sound IP phones, an IP telephony system for offices (photo 1).
e-Sound IP phone is a strategic product aiming at voice quality that exceeds that of conventional subscriber telephones. The objective was not only to sweep away the preconception of "IP phones have bad sound quality," but to go further beyond. Fortunately, many visitors tested and praised the superior voice quality of the e-Sound IP phone. Watching the visitors, I was hit with a sense of nostalgia as I have been working on IP phones literally since incunabulum.
The road leading to the present was never easy. Standing at the booth, I had recalled memories of "VOICEHUB," the first IP telephony related product that I developed 10 years ago.
"Create a device that handles voice over LAN"
It was a day in August 1995 when I was standing blankly in front of my supervisor. He wanted me to examine whether we could create a system that handles voice over LAN.
Handle voice over LAN? The concept may seem nothing out of the ordinary at the present with the widespread of personal IP telephony services; however, the request exceeded the boundaries of common sense for me at the time. No, it was a request that would have exceeded the boundaries of common sense for everyone-inside the company and out-not just me.
In order to handle voice over LAN, it had to be converted to packets in the same manner as computer communication. There have been researches on voice packet technology, and it was known that with IP communication, packets at times do not reach the other party. This led to voice intermittence. Unlike data, voice simply cannot be resent. Furthermore, voice packets being researched at the time were based on the concept of sending only portions present with sound during the actual communication, in order to save used bandwidth. Detecting this presence of sound is difficult, leading to a phenomenon called "start-up distortion" where the beginning of a conversation is cut-off and not played back properly. Practical application of voice packets was considered virtually impossible.
For this reason, another technology referred to as ATM (Asynchronous Transfer Mode), built with a system that maintains quality of voice communication, was assumed to become the future trend. ATM is a method that sends data, such as voice, by converting them into packets of fixed length. The technology enables communication to be processed using hardware to minimize packet loss and latency. Many thought that voice and data can be integrated using ATM.
As I stood blankly, my supervisor continued, "We are entering the PC era. The LAN device market will also expand. In the not-too-distant future, prices will drop and what was available only as commercial use will be opened to the general public." His tone became firm, "This is where 'voice' comes in. Voice traffic is overwhelmingly smaller than data traffic. I assure you: there will come a day when voice is integrated with data network including the Internet."
Continued to next page: Frequent visits to Takasaki to learn computers...
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