Queuing techniques are procedures for balancing peak loads in network segments. If a network segment is overloaded, queuing technology is used to insert buffers in the switching devices such as routers or switches. The corresponding router is told how to handle the data.
There are several queuing methods: with the normally used FIFO queuing, First In First Out (FIFO), overload situations lead to the discarding of data packets, regardless of their application. With Fair Queuing( FQ), control means are used by the TCP protocol to reduce the load before a queue is completely full. In addition, Weighted Random Early Detection(WRED) is a weighted queuing(WFQ) method that resolves congestion situations by setting priorities.
Other queuing strategies include Weighted Fair Queuing (WFQ) for prioritizing data packets and Weighted Round Robin Queuing(WRR), also known as Class-Based Queuing( CBQ). A queuing method used in the Resource Reservation Protocol( RSVP) is Class-Based Weighted Fair Queuing( CBWFQ), which can perform classification according to traffic classes.