The Avaya TN742 is an 8-port analog line circuit pack for Avaya Definity/CM systems, delivering eight analog voice trunk interfaces that connect standard analog telephones and other line devices to the PBX. Installed as a circuit pack in the system cabinet, it expands the trunk capacity of the Avaya telephony platform and is documented in Avaya manuals as an Analog Line board (board type code TN742). Variants and vintages include TN742V18 and the documented V1–V3 revisions, reflecting its long‑standing use across multiple CM/Definity configurations.
