This parameter controls the generation of F4/F5 AIS and RDI due to lower order problems such as physical layer problems. For AIS: Defines if F4/F5 AIS cell is transmitted due to problems such as physical layer alarm or F4/F5 defect. This is applicable for all ports . off - Problems in this port will not trigger F4/F5 AIS transmition to the ajacent port (e.g. from USER to NETWORK) of a VPC/VCC. on - Problems in this port will trigger F4/F5 AIS transmition to the ajacent port (e.g. from USER to NETWORK) of a VPC/VCC. For RDI: Defines if F4/F5 RDI cell will be transmitted due to physical layer problems in that port (in addition to F4/F5 RDI cells transmitted due to ATM layer problems). For example, If it is enabled for Network port, then physical layer defect will initiate the transmission of F4/F5 RDI cell back to the trunk. The type of F4/F5 (Segment or End-to-End) is according to the configuration of the VPC/VCC.