Definity TN577
Provides 4 RS-423 physical ports for X.25 protocol interfaces between the system and adjuncts Functions as the data communications interface unit providing protocol conversion between the X.25 protocol and the mode 3 protocol carried across the LAN bus X.25 protocol (Levels 1 and 2) is terminated and the data reformatted into the ISDN packet mode protocol for transport across the LAN bus. Supported adjuncts include Audix, CMS, and Message Server Adjunct (MSA) Supports the Distributed Communications System (DCS) environment by providing X.25 signaling through 1 of the RS-423 physical ports, or back through the system using the TDM Bus to appropriate DS1 or tie trunk circuit pack