Which IOS queuing method uses four fixed/static queues for congestion handling?

Priority queuing (PQ) uses four fixed queues: high, medium, normal, and low. Packets in the high-priority queue are always serviced first until it is empty, then the medium queue, and so on. This ensures that critical traffic receives preferential treatment. However, it can lead to starvation for lower-priority traffic if the higher-priority queues are continuously full. Weighted Fair Queuing (WFQ) provides fair bandwidth allocation to all flows. Custom Queuing allows for user-defined queue sizes and bandwidth percentages. Low Latency Queuing (LLQ) combines PQ for real-time traffic with WFQ for other traffic, offering a more balanced approach than pure PQ.