exchange termination (ET)

An Exchange Termination(ET) is the exchange termination with the higher switching functions. It is the interface between the line termination and the exchange unit.

The exchange termination separates the B channels of the ISDN and forms the termination of the D channel. The Exchange Termination forms the physical and logical boundaries between the Digital Local Loop( DLL) and the local exchange. The functionality of the exchange termination in the local exchange corresponds to that of the network terminations( NT) at the user.