This attribute gives the priority that a path holds once it is
established. Zero (0) is the highest priority and four (4) is the
lowest. A path's holdingPriority determines its likelihood of being
bumped by a new path to acquire its bandwidth. The setupPriority, a
complementary attribute, indicates the priority of a path at
establishment time. A new path can bump an existing path if the
new path's setupPriority is higher (or numerically less) than the
existing path's holdingPriority.