ITU G.775:1998 Loss Of Signal (los) And Alarm Indication Signal (ais) And Remote Defect Indication (rdi) Defect Detection And Clearance Criteria For Pdh Signals Gives recommended criteria for detecting and clearing LOS, AIS and RDI defects at intra-station interfaces complying with Rec. G.703, operating at bit rates covered in Rec. G.702. Applies to new desig