ISDN is an acronym, borrowed from the original German translation meaning Integrated Speech and Data Net. ISDN actually breaks down into three different parts:

Integrated Services: talks about ISDN’s ability to deliver at least two simultaneous connections, from data, voice, fax, or video over one line. Many different devices can be attached to a single line which allows peoples communication needs be met without the purchase of extra cluttered lines.

Digital: is the type of transmission. Rather than there being an analog line in phones or the analog access in an ISP, the whole thing is digital requiring no conversion. There is also no static or nose to slow the transmission speed.

Network: ISDN has none of the downfalls of a point to point leased line. Rather, ISDN extend from the telephone line to a remote user and have all the pivot points and switching equipment in between.

ISDN service comes in three different categories bearer service, supplementary services, and teleservices.

ISDN is a circuit switched telephone network which allows digital transmission over ordinary telephone wires. This results in better quality, higher speeds, as well as a delineated set of protocols for establishing connections and for advanced call features for the user. Used in videoconferences, ISDN provides voice, video, and text allowing for all three to be implemented.

If you were thinking about advantages and disadvantages of ISDN, it would have to start and end with quality. While this is a futuristic technology which has only been dreamed up in science fiction, it’s a technology which is still in its infancy so there are obvious kinks to be worked out.

ISDN can be best explained in internet chat rooms with experts or going back in a publications history of published articles. If you’re looking to configure a firewall with an ISDN modem, you should first make sure that firewall protection wouldn’t be breeched in one of the platforms, such as the phone line, fax line, etc.

While I don’t know where you could find free ISDN ISP’s you could certainly check around on the internet for cheap options for both your ISP’s and your ISDN simulators.

The future of ISDN, I don’t know that it will continue in its present format, though I do think it will survive. The transmission and communication of information from platform to platform simultaneously is too new an animal to dissect just yet. Though I know we wish we could.