Class differentiation is a tremendous issue as a consequence of diverse applications and the drastically grow of traffic demands. Thus, this paper investigates this radical evolution with intensive explanation in order to define a suitable paradigm for class differentiation provisioning. It also investigates the possibility of having classified packet priorities for resolving packet contention. This paper proposes a preemptive hybrid scheduling scheme for optical packet switch. This paper present a preemptive scheme with less complexity and independent of traffic load when p les 0.4. This hybrid technique can be realized via the implementation of fully convertible tunable optical wavelength converter (TOWC). This mechanism is equipped with recirculation by employing fiber delay lines. Three different classes of traffic are introduced. Class differentiation can be achieved by classifying packet priority. This proposed scheme ensures packet loss probability for class 1 traffic remains below 10-12 and independent of traffic load for p les 0.4. The results have been demonstrated via simulation and compare with the conventional baseline system. This scheme ensures that class 1 traffic is preempted in packet contention scenario. It guarantees class 1 traffic is exempted from unnecessary wavelength that tends to degrade the quality of the signal and conventional buffering delay. It is a very promising scheme especially for real-time delivery