The unit is capable of sending a pseudorandom test pattern (511 or QRSS) out the WAN and monitoring the WAN received data for the same pattern. The BERT pattern may be selected to occupy either the full T1 payload or only the bandwidth allocated to the DTE (fractional T1). When a unit is sending this BERT, the receiver will monitor and characterize the incoming signal for the same BERT pattern. In Frame Relay applications the unit will not preserve the LMI path during this diagnostic and in-band management may not operate. This test may be ineffective in certain frame relay environments as pseudorandom data lacks appropriate framing. Refer to VLOOP and VBERT for PVC-based error-rate testing in a live frame relay network. (1) Start a BERT test on full T1 - replaces entire T1 payload with the configured BERT pattern while monitoring the full T1 bandwidth (1.536M) for the presence of the BERT pattern. (2) Start a BERT test on fractional T1 - replaces only the protion of the T1 payload that has been allocated to the DTE with the configured BERT pattern while monitoring the same T1 bandwidth (DTE Data Rate) for the presence of the BERT pattern. (3) Stop a BERT test. (4) Inject a single bit error into the outgoing pattern. (5) Clear current BERT results.