The network-wide priority of this clock source if configured
as a source of network clock for NCDP. The highest priority
clock source is that clock source having the lowest positive
numeric value. The clock source with the highest priority is
selected as the root of the clock distribution tree by the NCDP
algorithm. If more that one clock source is configured with
with the same priority the NCDP algorithm uses the value
'cwnAtmSourceStratum' as a tiebreaker.