Reason-param,Protocol,Reason-Text,Reference
Cause=1,Preemption,UA Preemption,[RFC4411]
Cause=2,Preemption,Reserved Resources Preempted,[RFC4411]
Cause=3,Preemption,Generic Preemption,[RFC4411]
Cause=4,Preemption,Non-IP Preemption,[RFC4411]