What is the electronic tandem network (ETN)?

The Electronic Tandem Network (ETN) is a private network configuration. It provides for the interconnection of customer locations (PBXs/Centrexes) via dedicated intertandem tie trunks, access tie trunks, and FX, WATS and CO trunks. Automatic Route Selection (ARS), Authorization Codes (AC), etc. are some of the features available with ETN.