With so much the telecommunication services variety, then ISDN now to appear as a major telecommunications network. ISDN is a single network that to be able for handling multimedia services such as voice, data, video and facsimile. Key of ISDN is a service digitalization, transmission, switching and signaling. In this case computer part become very dominant.
We now at this moment the main and larger international communication infrastructure is telephone network, because of that, ISDN planed to perform design develop and telephone network plan that already to be available right now to the system with end-to-end digital connectivity. Of course that change is not easy and cannot be happen quickly. At this moment, although the digital telephone system already many implemented, but because the investment is expensive, then many country to perform change step by step. So that ISDN until a couple of year in the future must still to operated side by side with available analog telephone network. All this directly to show that standard for ISDN must produces as good as possible before implemented. That aspect already recognized by CCITT and the first recommendation about ISDN recommended on 1984, then perfected again on 1988.
Perhaps ISDN to represent important example from contribution of computer technology to telecommunication, and this could be to represent very important development as result from combining between computer technology and communication. Utilization computer with big scale on ISDN already to spur on created Intelligent Network (IN) concept that programmed for adaptively, algorithmic, clever, responsive, and intelligent. Example ability that maybe to perform by IN is usually known as “real time translation machine”. A telephone conversation that the original language is in Japanese language can be hearing directly in English language in the receiver and on the contrary. A telex that sends in Indonesian language from Jakarta will be delivered to Solo in Javanese language. That example, although at this moment still to consider as excessive imagination, to guess will possible to realized on 21-century coming up.
Telecommunication network already to realize rapidly grow at last 150 year and will keep grow to larger services on better form in the future century. Information form that will show in the future is very depending on telecommunication development and need a services variety on that moment. To guess that millions dollar will invest by many countries in two-decade coming up for development the telecommunication system facilities. We apparent will soon to go in to high tech telecommunication era.
