Hypertec ISDN 10T Router manual Physical Interface, Isdn Switch Variants

Concepts and Principles of Operation

Physical Interface

The ISDN physical interface is a available in two types, U and S/T. The S/T interface relies on a external device called NT1 to connect the user equipment to the ISDN line. The S/T interface is used in most parts of the world. The U interface, widely used in North America, is designed for user equipment with built-in NT1. The NT1 (also called ISDN DSU) built-in ISDN device is also allowed In Japan. The Japanese U interface however works differently from the rest of the world.

ISDN Switch Variants

When your Hypertec Router is delivered, it is preset to use a default ISDN variant. The ISDN variant is the type of ISDN operation run by your Telephone company.

Interface Type	National ISDN Variants	Default Setting
U	North American	National ISDN
S/T	Japan	NTT
S/T	Rest of the World	EURO-ISDN

You must have the right ISDN variant (switch) configured as provided by your ISDN service provider or telephone company.

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