What does ISDN mean?

ISDN is the abbreviation of "Integrated Services Digital Networks", or "Integrated Digital Services Network", and is a term created by the ITU-T organization. In practice, it is a totally digital transformation of the current telephone network, exploiting the existing switching systems and wiring.

What are Terminal Adapters (Terminal Adapters, TA)?

It is always good to remember that you can use the existing telephones, modems and faxes on ISDN lines. The terminal adapters (in particular those that we are now considering are also called "a / b adapters") are used precisely to make the channels "B" suitable to work with the normal POTS (Plain Old Telephony Services) telephones, that is to say the our old disk or keyboard devices, analogue modems and Group 3 faxes.

Often the terminal adapter is integrated into ISDN "modems" - note that "modem" is an improper definition, since it is not MDdulan, nor DEModulan, then we will talk about "ISDN cards", or better yet " TA data "-, but we are more frequently asked to install the so-called" Borchia NT1 + ", which contains TA for two analog lines. There are cases in which there is no need to interface with existing terminals or emulate them, and there can be devices with synchronous interfaces present. In these cases, stand-alone units or computer interfaces can provide synchronous connections to B channels without conversion to asynchronous standards.