Avaya TN429D DIOD (Direct Inward/Outward Dialing)

The TN429D provides eight ports for direct inward/outward dialing (DIOD) trunks. Each port provides a two-wire interface to the central office (CO) public exchange for incoming and outgoing calls. CO provides caller names and numbers to the TN429D, which displays the on Definity digital voice terminals (DCP and BRI) equipped with a thirty-two- or forty-character alphanumeric display and with System 25/Merlin 7315H and 7317H terminals supported by Definity.