What is an NT-1 line and how do I use it?
A. NT-1 stands for “Networking Terminal type 1.” The NT-1 is a little plastic box with LEDS and is usually purchased separately. The NT-1 is a device which converts the two-wire line (or U interface) which comes from the telephone company, into a four-wire line (ST interface). The NT-1 is physically connected between the ISDN board of your videoconferencing system and your ISDN phone line. The NT-1 supports network maintenance functions, such as loop testing. Up to eight terminal devices may be addressed by an NT-1.
