Two priority schemes for fair distributed queue (FDQ) networks

The absolute priority scheme is message preemptive and allows only the highest priority class to be present on the network under heavy load. The allocation priority scheme permits the transmission of low priority class data in a controllable proportion to the high priority data. Under heavy load, both schemes allocate equal bandwidth to the active nodes within each priority class without wasting bandwidth. They also have completely predictable worst-case delays. The delay characteristics of both schemes under Poisson load are studied via simulation. With the assumption of equal arrival rates, the high priority class achieves a much lower delay than the low priority class, in both schemes. Thus, the absolute and allocation priority schemes are fair and very efficient