The four-wire interface of ISDN line terminated by an NT-1 circuit. (See also U- interface and NT-1)
The eight-pin RJ-45 connector on the “back side†of an NT-1 or ISDN adapter that connects one or more ISDN adapters to the NT-1. Of the eight pins on the RJ-45 connector, the outside two pins on each side provide power, and the center four form a “transmit†and “receive†pairs. ISDN adapters with built-in NT-1s do not have an S/T Interface.
The standard interface between ISDN terminals or terminal adapters and the network channel termination.
The electrical interface between a network terminator (NT1) device and one or more ISDN communications devices that do not contain their own NT1s.
Subscriber/Transport interface.The boundary between the user and an ISDN network.
A four-wire ISDN BRI interface presented to the customer by the PTTs in non-North American markets.
An interface (connector) on the DSU for connecting to an ISDN device. While analog telephones, modems and PCs can be daisy-chained easily, ISDN devices cannot be connected without this interface. ISDN devices can be connected via the S/T connectors using Ethernet cables. No special configuration is required, except that incoming calls need to be blocked on one of the ISDN devices. Let's suppose there are ISDN Device A and ISDN Device B, and Analog Port 1 of Device A is now in use to receive a cal. Despite this configuration, Analog Port 1 of Device B will receive any incoming call; the user thus needs to manually disable the dial-in function of the latter port using a configuration utility, etc. Note that many terminal adapters or dial-up routers with a built-in DSU require an option board for the interface.
System reference point/terminal reference point interface. A four-pair connection between the ISDN provider service and the customer terminal equipment.
