No discussion of traffic shaping would be complete without mentioning the different types of queues that can be utilized. The most basic queuing policy is a FIFO queue, sometimes also referred to as first come, first served (FCFS) queuing. With FIFO queuing, no packet is given priority; nor are there different classes of traffic. All packets are treated equally within the FIFO queue and packets are sent out in the order that they arrive.
Obviously, this makes for a very easy to implement policy. But when implemented, it can result in some users and applications consuming all the bandwidth. Even when they are not consuming bandwidth constantly, their usage may spike at inopportune times, delaying time-sensitive and important ...
