[ITU-T Q.850 Code] 99 [Enumeration] IE_NONEXIST [Cause] Information element / parameter non-existent or not implemented [Q.850] [Description] 
This cause indicates that the equipment sending this cause has received a message which includes information element(s)/parameter(s) not recognized because the information element(s)/parameter name(s) are not defined or are defined but not implemented by the equipment sending the cause. This cause indicates that the information element(s)/parameter(s) were discarded. However, the information element is not required to be present in the message in order for the equipment sending the cause to process the message.