In the meantime, the industry-first IP-PBX "IPstage" was completed. IPstage is presently a very successful product that is deployed by a wide range of customers, and is a product that we take pride in. Nevertheless, we encountered problems with the product in its early stages.

I strongly feel it was the customers that turned our IPstage into what it is today. I would like to take this opportunity to show my gratitude towards the customers during the early stages for their patience despite the many inconveniences we have caused, as well as their kind support over the years.

As the shipment judgment ended on February 14, examination for the development method of the next IPstage version (V2) started. The shipment of V2 was already decided for end of July, in five and a half months. The main feature was accommodation of a private branch PHS terminal.

Indeed, we suffered a great deal during this development as well. But before introducing that story, allow me to talk a little about the technical conditions.

Communication without distinction of fax or modem

Various communication devices other than telephones are used in company networks, including fax machines, dial-up modems and special devices utilizing modem signals. And these are all analog devices.

During the design of IP-PBX, we had the option of allowing communication by supporting each of these devices. The concept was to perform fax exclusive processing for fax and modem exclusive processing for modem. However, we felt that IP telephony systems would not spread widely if we could not design a structure that could accommodate these communication devices as they were (Fig. 1).

Such perspective led to the basic concept of guaranteeing communication regardless of the signal attribute including modems and faxes for data flowing through a network.

In the case of voice, it is sufficient if it can be distinctively heard by the human ears. In other words, there is no need to completely guarantee the wave patterns. On the other hand, it is necessary to reproduce the wave patterns of faxes and modems since they contain information in the waves themselves.

Hence, we created a system that allows self-synchronization among devices installed on a LAN. In other words, we built a system that matches the clock of devices installed on a LAN. The special LSI realizes this function. It is also the characteristic of the first VoIP-LSI created by OKI.