The mode in which the transmit queue arbiter services the
queues. When in strict-mode, the queues will be services
by numerical priority from lowest to highest. Lower priority
queues will not be services until the current queue is drained.
When set to weightedFairQ, the number of slices in a
particular queue determines the frequency of servicing.
A slice configuration of 00-00...100 will set the port to
strict-mode. When in enhancedTransmission mode the
non-enhanced transmission queues are serviced first using
low latency or strict priority. The remaining bandwidth
is then allocated to the enhanced transmission queues using
weightedFairQ.