This attribute gives the priority at which a path is established.
Zero(0) is the highest priority and four(4) is the lowest. When
PORS establishes a path through the network, it uses the
setupPriority attribute to determine its potential for bumping
established paths to acquire their bandwidth. The holdingPriority, a
complementary attribute of this component, indicates the priority a
path maintains once it is established. A new path can bump an
existing path if the new path's setupPriority is higher (numerically
less) than the existing path's holdingPriority.