Priority Queuing (PQ) creates queues with strict priority levels. Higher priority queues are always serviced first.
How PQ works:
- Traffic classified into high, medium, normal, low
- Scheduler empties highest priority first
- Lower queues served when higher are empty
PQ advantages:
- Simple to configure
- Lowest latency for high priority traffic
- Voice never waits behind data
PQ disadvantages:
- Lower priority traffic can starve
- If high priority is constant, nothing else transmits
- No bandwidth guarantees for lower classes
PQ scheduler runs in time for priority levels. Space is for buffered packets.