The DS1/DS3 ATM Interface Module enables the FIREBERD 6000 Communications Analyzer to test ATM circuits and equipment operating at the DS1 rate of 1.544 MHz as well as the DS3 rate of 44.736 MHz. The module is capable of performing the following tests: • DS 1 and DS3 physical layer analysis including line and framing error detection, alarm indicators, etc. • TC sub-layer tests include PLCP and HEC based cell mapping; PLCP alarms, statistics and error insertion; and HEC generation, checking, and erroring. • ATM layer tests include transmitting and receiving cells with a pre-defmed or user-defined payload, measuring cell round trip delay and traffic shaping conformance per ATM Forum GCRA requirements, monitoring lost or misinserted cells, generating/receiving OAM cells, and automatic scanning of active VPI/VCIs. • AAL layer tests include automatically recognizing AAL1, 3/4, or 5 activity on a selected VPI/VCI, and acquiring AAL1, 3/4 or 5 SAR PDU and AAL 3/4 or 5 CS PDU statistics. Support for IEEE 488.2 control is incorporated into the FIREBERD 6000 and can be used to control and monitor DS1/DS3 ATM Interface Module.