The Quad T1/PRI module combines with other ATLAS components to implement a variety of WAN access products, including a T1 Bandwidth Manager, an ISDN Access Switch, and a Digital Access Cross-connect System (DACS). The module provides four network ports, each of which can be independently configured to operate in T1 (DS-1 or DSX-1) or Primary Rate ISDN (PRI) modes. The Quad T1/PRI module can perform T1- to-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 Quad T1/PRI module, ATLAS operates in a DACS mode supporting DS0 time slot interchange and DS0 grooming while preserving robbed bit signaling. ATLAS can be fully populated with Quad T1/PRI modules to support a pure DACSing application of 34 T1 circuits. Configuration of the Quad T1/PRI module can be accomplished through a variety of mechanisms, including Telnet or VT100 emulation. SNMP management is supported for alarm and event reporting. Extensive T1 circuit monitoring is standard with the Quad T1/PRI module, including the ability to detect, store, and report all performance parameters specified in AT&T Technical Reference 54016. The module detects and reports alarm conditions associated with the circuit, including Loss of Signal, Red Alarm, Blue Alarm, Yellow Alarm, and for PRI circuits, D-Channel Synchronization. The Quad T1/PRI module responds to standard loopback commands from the telephone company central office - both in-band commands and those sent through the Facilities Data Link. In addition, local and remote loopbacks (both line and payload) can be initiated from ATLAS. When testing the T1 circuit, the Quad T1/PRI module allows the user to select from a variety of test patterns, including all 1s, all 0s, and a standard QRSS pattern. When sending the QRSS pattern, the Quad T1/PRI module records and reports the results of the testing to the user.