Yesterday’s QoD:
Which of the following is NOT an example of congestion management?
Here are the results:
| Answer | % |
| Resource Reservation Protocol (RSVP) | 55% |
| FIFO queuing | 40% |
| Weighted fair queuing (WFQ) | 4% |
| Priority queuing (PQ) | 1% |
The answer: Resource Reservation Protocol (RSVP)
Congestion Management
Congestion management features operate to control congestion once it occurs. One way that network elements handle an overflow of arriving traffic is to use a queuing algorithm to sort the traffic and then determine some method of prioritizing it onto an output link. Each queuing algorithm is designed to solve a specific network traffic problem and has a particular effect on network performance.
The Cisco IOS software congestion management, or queuing, features include the following:
•FIFO queuing
•Priority queuing (PQ)
•Frame Relay permanent virtual circuit (PVC) interface priority queuing (FR PIPQ)
•Custom queuing (CQ)
•Weighted fair queuing (WFQ) and distributed WFQ (DWFQ)
•Class-based WFQ (CBWFQ) and Distributed CBWFQ (DCBWFQ)
•IP RTP Priority
•Frame Relay IP RTP Priority
•Low Latency Queuing (LLQ)
•Distributed LLQ (DLLQ)
•LLQ for Frame Relay
