ISDN, Integrated Services Digital Network     Last updated on          


Rarely used MSN [Multiple Subscriber Numbering] ISDN-service allows to map up to 8 separate-phone-numbers on one ISDN PRI (BAI) installation. However, only 2 B-channels are available, therefore only 2 devices can be connected at one time (simultaneously). AO/DI, Always On/Dynamic ISDN service allows always-on one data-channel(D-channel, 16kbps). One B-channel will be awake if D-channel demands. D-channel is used for specific purposes – controlling, e-mailing, and signaling. Another ISDN service is D-channel/X.25 protocol, mostly used for e-mailing.

Note: ISDN estimated operating cost: 0.5 US$ per hour (for one 64kbps-channel) in Thailand [Bangkok Post, Sept. 5, 2001]



FS . Apple: several ISDN hardware vendors support Mac OSs;

FS . Linux: several ISDN hardware vendors support RedHat and SuSe;;

FS . Microsoft Windows 3.x: Not recommended; USB port is not supported by Windows 3.1;

FS . Microsoft Windows 9x & Microsoft Windows NT: Almost all ISDN hardware vendors support Windows 9x/NT platform; After hardware is being installed, run  Add New Hardware to detect PnP device or not; and then install the device’s driver; ; For more information: ;