Priority Queue¶

The PriorityQueue module is a compound module that implements priority queueing with the help of a classifier submodule, multiple queues and a scheduler.

It contains a configurable number of PacketQueue’s. A PacketClassifier module classifies packets into the queues according to the configured packet classifier function. A PriorityScheduler pops packets from the first non-empty queue, thus earlier queues have a priority over the later ones.

In this example network, packets are produced at random intervals by an active packet source (ActivePacketSource). The source is connected to a priority queue (PriorityQueue) with two inner queues (PacketQueue). The packets are collected at random intervals by an active packet sink (ActivePacketSink).

../../../_images/PriorityQueue_Queue.png

network PriorityQueueTutorialStep
{
    @display("bgb=600,200");
    submodules:
        producer: ActivePacketSource {
            @display("p=100,100");
        }
        queue: PriorityQueue {
            @display("p=300,100");
        }
        collector: ActivePacketSink {
            @display("p=500,100");
        }
    connections allowunconnected:
        producer.out --> queue.in;
        queue.out --> collector.in;
}

[Config PriorityQueue]
network = PriorityQueueTutorialStep
sim-time-limit = 10s

*.producer.packetLength = 1B
*.producer.productionInterval = uniform(0s, 2s)
*.queue.numQueues = 2
*.queue.classifier.typename = "WrrClassifier"
*.queue.classifier.weights = "1 1"
*.collector.collectionInterval = uniform(0s, 2s)