The priority threshold value to be compared against
the 3 bits of priority contained in each packet's SRP
header. If a packet's priority is greater or equal to
this threshold, that packet should be placed in the
high priority transmit or transit queue. If a packet's
priority is less than this threshold, it should be
placed in the low priority transmit or transit queue.
Since there are only two types of priority
queues (High Priority and Low Priority) a packet
is treated as either low or high priority once it is
on the ring. Each node determines the threshold
value for classifying what is considered a high
priority packet and what is considered a low priority
packet.