DESC: The Dual T1/PRI module combines with other ATLAS components to implement a variety of WAN access products, including a T1 Bandwidth Manager, an ISDN Switch, and a Digital Access Cross-Connect System (DACS). The module provides two user ports, each of which can be independently configured to operate in T1 (DS-1 or DSX-1) or Primary Rate ISDN (PRI) modes. ??The Dual T1/PRI module can perform T1 or PRI conversion, translating between the robbed-bit signaling presented in a channelized T1 circuit and the D-channel signaling of a PRI circuit. When using the Dual T1/PRI module, ATLAS operates in a DACS mode supporting DSO time slot interchange and DSO grooming while preserving robbed bit signaling. ATLAS can be fully populated with T1/PRI modules to support a pure DACSing application of 10 FT1 circuits or 4T1s.