Value of precedence being applied on IP header.
<0-7> Value of precedence
routine Specify routine precedence(0)
priority Specify priority precedence(1)
immediate Specify immediate precedence(2)
flash Specify flash precedence(3)
flash-override Specify flash-override precedence(4)
critical Specify critical precedence(5)
internet Specify internetwork control precedence(6)
network Specify network control precedence(7)
Setting -1 indicates closing this action.